Author: "Bournaud, F." / Topic: astrophysics - Searchworks@Jio Institute Digital Library Search Results

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42 results on '"Bournaud, F."'

1. On the frequency, intensity and duration of starburst episodes triggered by galaxy interactions and mergers

Author: Di Matteo, P., Bournaud, F., Martig, M., Combes, F., Melchior, A. -L., and Semelin, B.
Subjects: Astrophysics
Abstract: We investigate the intensity enhancement and the duration of starburst episodes, triggered by major galaxy interactions and mergers. To this aim, we analyze two large statistical datasets of numerical simulations. These have been obtained using two independent and different numerical techniques to model baryonic and dark matter evolution, that are extensively compared for the first time. One is a Tree-SPH code, the other one is a grid-based N-body sticky-particles code. We show that, at low redshift, galaxy interactions and mergers in general trigger only moderate star formation enhancements. Strong starbursts where the star formation rate is increased by a factor larger than 5 are rare and found only in about 15% of major galaxy interactions and mergers. Merger-driven starbursts are also rather short-lived, with a typical duration of the activity of a few 10^8 yr. These conclusions are found to be robust, independent from the numerical techniques and star formation models. At higher redshifts where galaxies contain more gas, gas inflow-induced starbursts are neither stronger neither longer than their local counterparts. In turn, the formation of massive gas clumps, results of local Jeans instability that can occur spontaneously in gas-rich disks or be indirectly favored by galaxy interactions, could play a more important role in determining the duration and intensity of star formation episodes., Comment: 22 pages, 28 figures, A&A accepted. High resolution version available at http://aramis.obspm.fr/~paola/SFR_frequency/
Published: 2008
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2. Galaxy mergers at high resolution: From elliptical galaxies to tidal dwarfs and globular clusters

Author: Bournaud, F., Bois, M., Emsellem, E., and Duc, P. -A.
Subjects: Astrophysics
Abstract: Numerical simulations of galaxy mergers are a powerful tool to study these fundamental events in the hierarchical built-up of galaxies. Recent progress have been made owing to improved modeling, increased resolution and large statistical samples. We present here the highest-resolution models of mergers performed so far. The formation of a variety of substructures ranging from kinematically decoupled cores to globular-like clusters is directly resolved. In a resolution study, we show that the large-scale structure of elliptical-like merger remnants can be affected by the resolution, and a too modest resolution may affect the numerical predictions on the properties of major merger remnants: understanding precisely which kind of event or succession of events has formed the various types of elliptical galaxies remains an open challenge., Comment: To be published in the proceedings of the "Galactic and Stellar Dynamics 2008" conference. 4 pages
Published: 2008
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3. High-resolution simulations of galaxy mergers: Resolving globular cluster formation

Author: Bournaud, F., Duc, P. -A., and Emsellem, E.
Subjects: Astrophysics
Abstract: Massive star clusters observed in galaxy mergers are often suggested to be progenitors of globular clusters. To study this hypothesis, we performed the highest resolution simulation of a gas-rich galaxy merger so far. The formation of massive star clusters of 10^5 to 10^7 Mo, triggered by the galaxy interaction, is directly resolved in this model. We show that these clusters are tightly bound structures with little net rotation, due to evolve into compact long-lived stellar systems. Massive clusters formed in galaxy mergers are thus robust candidates for progenitors of long-lived globular clusters. The simulated cluster mass spectrum is consistent with theory and observations. Tidal dwarf galaxies of 10^8-9 Mo can form at the same time, and appear to be part of a different class of objects, being more extended and rotating., Comment: MNRAS letters accepted. Version with high-resolution figures available at http://aramis.obspm.fr/~bournaud/GC.pdf
Published: 2008
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4. Observations and modelling of a clumpy galaxy at z=1.6: Spectroscopic clues to the origin and evolution of chain galaxies

Author: Bournaud, F., Daddi, E., Elmegreen, B. G., Elmegreen, D. M., Nesvadba, N., Vanzella, E., Di Matteo, P., Tiran, L. Le, Lehnert, M., and Elbaz, D.
Subjects: Astrophysics
Abstract: We investigate the properties of a clump-cluster galaxy at redshift 1.57. The morphology of this galaxy is dominated by eight star-forming clumps in optical observations, and has photometric properties typical of most clump-cluster and chain galaxies. Its complex asymmetrical morphology has led to the suggestion that this system is a group merger of several initially separate proto-galaxies. We performed H_alpha integral field spectroscopy of this system using SINFONI on VLT UT4. These observations reveal a large-scale velocity gradient throughout the system, but with large local kinematic disturbances. Using a numerical model of gas-rich disk fragmentation, we find that clump interactions and migration can account for the observed disturbed rotation. On the other hand, the global rotation would not be expected for a multiply merging system. We further find that this system follows the stellar mass vs. metallicity, star formation rate and size relations expected for a disk at this redshift, and exhibits a disk-like radial metallicity gradient, so that the scenario of internal disk fragmentation is the most likely one. A red and metallic central concentration appears to be a bulge in this proto-spiral clumpy galaxy. A chain galaxy at redshift 2.07 in the same field also shows disk-like rotation. Such systems are likely progenitors of the present-day bright spiral galaxies, forming their exponential disks through clump migration and disruption and fueling their bulges. Our present results show that disturbed morphologies and kinematics are not necessarily signs of galaxy mergers and interactions, and can instead result from the internal evolution of primordial disks., Comment: A&A, accepted. Version with full resolution figures available at http://aramis.obspm.fr/~bournaud/udfr2.pdf -- Animation of clumpy galaxy models available at http://aramis.obspm.fr/~bournaud/cc/cc.html
Published: 2008
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5. Simulations of galactic disks including a dark baryonic component

Author: Revaz, Y., Pfenniger, D., Combes, F., and Bournaud, F.
Subjects: Astrophysics
Abstract: $\Lambda$CDM numerical simulations predict that the "missing baryons" reside in a Warm-Hot gas phase in the over-dense cosmic filaments. However, there are now several theoretical and observational arguments that support the fact that galactic disks may be more massive than usually thought, containing a substantial fraction of the "missing baryons". Hereafter, we present new N-body simulations of galactic disks, where the gas content has been multiplied by a factor 5. The stability of the disk is ensured by assuming that the ISM is composed out of two partially coupled phases, a warm phase, corresponding the observed CO and HI gas and a cold collisionless phase corresponding to the unseen baryons., Comment: 4 pages, 2 figures. To appear in the proceedings of "Formation and Evolution of Galaxy Disks", ed. J. Funes & E. Corsini. Higher resolution version may be downloaded at https://obswww.unige.ch/~revaz/public/Rome2007/revaz.pdf
Published: 2008
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6. Rapid formation of exponential disks and bulges at high redshift from the dynamical evolution of clump cluster and chain galaxies

Author: Bournaud, F., Elmegreen, B. G., and Elmegreen, D. M.
Subjects: Astrophysics
Abstract: Many galaxies at high redshift have peculiar morphologies dominated by 10^8-10^9 Mo kpc-sized clumps. Using numerical simulations, we show that these "clump clusters" can result from fragmentation in gravitationally unstable primordial disks. They appear as "chain galaxies" when observed edge-on. In less than 1 Gyr, clump formation, migration, disruption, and interaction with the disk cause these systems to evolve from initially uniform disks into regular spiral galaxies with an exponential or double-exponential disk profile and a central bulge. The inner exponential is the initial disk size and the outer exponential is from material flung out by spiral arms and clump torques. A nuclear black hole may form at the same time as the bulge from smaller black holes that grow inside the dense cores of each clump. The properties and lifetimes of the clumps in our models are consistent with observations of the clumps in high redshift galaxies, and the stellar motions in our models are consistent with the observed velocity dispersions and lack of organized rotation in chain galaxies. We suggest that violently unstable disks are the first step in spiral galaxy formation. The associated starburst activity gives a short timescale for the initial stellar disk to form., Comment: ApJ Accepted, 13 pages, 9 figures
Published: 2007
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7. Missing Mass in Collisional Debris from Galaxies

Author: Bournaud, F., Duc, P. -A., Brinks, E., Boquien, M., Amram, P., Lisenfeld, U., Koribalski, B. S., Walter, F., and Charmandaris, V.
Subjects: Astrophysics
Abstract: Recycled dwarf galaxies can form in the collisional debris of massive galaxies. Theoretical models predict that, contrary to classical galaxies, they should be free of non-baryonic Dark Matter. Analyzing the observed gas kinematics of such recycled galaxies with the help of a numerical model, we demonstrate that they do contain a massive dark component amounting to about twice the visible matter. Staying within the standard cosmological framework, this result most likely indicates the presence of large amounts of unseen, presumably cold, molecular gas. This additional mass should be present in the disks of their progenitor spiral galaxies, accounting for a significant part of the so-called missing baryons., Comment: Published in Science. Complete manuscript with appendix available at http://www.uni-sw.gwdg.de/~paduc/articles/bournaud_tdg_dm.pdf . Published online in Science Express May 10 issue at http://www.sciencemag.org/sciencexpress/recent.dtl
Published: 2007
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8. An almost head-on collision as the origin of two off-centre rings in the Andromeda galaxy

Author: Block, D. L., Bournaud, F., Combes, F., Groess, R., Barmby, P., Ashby, M. L. N., Fazio, G. G., Pahre, M. A., and Willner, S. P.
Subjects: Astrophysics
Abstract: The unusual morphology of the Andromeda Spiral (Messier 31, the closest spiral galaxy to the Milky Way) has long been an enigma. Although regarded for decades as showing little evidence of a violent history, M~31 has a well-known outer ring of star formation at a radius of 10 kpc whose center is offset from the galaxy nucleus. In addition, the outer galaxy disk is warped as seen at both optical and radio wavelengths. The halo contains numerous loops and ripples. Here we report the discovery, based on analysis of previously-obtained data, of a second, inner dust ring with projected dimensions 1.5 by 1 kpc and offset by ~0.5kpc from the center of the galaxy. The two rings appear to be density waves propagating in the disk. Numerical simulations offer a completely new interpretation for the morphology of M31: both rings result from a companion galaxy plunging head-on through the center of the disk of M31. The most likely interloper is M32. Head-on collisions between galaxies are rare, but it appears nonetheless that one took place 210 million years ago in our Local Group of galaxies., Comment: Published in Nature, October 19th issue. Higher resolution figures available at http://aramis.obspm.fr/~bournaud/M31_block_highres.pdf
Published: 2006
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9. From Tidal Dwarf Galaxies to Satellite Galaxies

Author: Bournaud, F. and Duc, P. -A.
Subjects: Astrophysics
Abstract: Cosmological models have granted dwarf galaxies a key role: their properties constrain the distribution of dark matter and the physical evolution of their hosts. There is increasing evidence that objects with masses of dwarf galaxies form in the tidal tails of colliding galaxies and speculations that they could become satellite-like galaxies around their progenitors and thus be cosmologically important. Yet, whether these "Tidal Dwarf Galaxies" (TDGs) candidates are really long-lived and not only present in young interacting systems is still an open question to which numerical simulations may give answers. We present a set of 96 simulations of colliding galaxies with various mass ratios and encounter geometries, and statistically study the evolution of their TDG candidates. Among the 593 substructures initially identified in tidal tails, about 75% fall back onto their progenitor or are disrupted in a few 10^8 years. The remaining 25% become long-lived bound objects that typically survive more than 2Gyr with masses above 10^8 M_sun. These long-lived, satellite-like objects, are found to form in the outer most regions of the tidal tails. We infer several basic properties that dwarf galaxies should meet to have a tidal origin and apply these criteria to the Local Group dwarfs. We also find that the presence of TDGs would foster the anisotropy observed in the distribution of satellite galaxies around their host. Identifying the conditions required for interacting systems to form long-lived tidal dwarfs, we roughly estimate their contribution to the overall population of dwarfs. We conclude that a small but significant fraction of them - typically a few percent, and possibly more in dense environments or around early-type galaxies - could be of tidal origin., Comment: Accepted for publication in A&A. Shortened abstract below, full version in the paper. Figs 1, 6, 7 at end fo manuscript
Published: 2006
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10. Stellar kinematics for the central spheroid in the Polar Disk Galaxy NGC4650A

Author: Iodice, E., Arnaboldi, M., Saglia, R. P., Sparke, L. S., Gerhard, O., Gallagher, J. S., Combes, F., Bournaud, F., Capaccioli, M., and Freeman, K. C.
Subjects: Astrophysics
Abstract: We have obtained high angular resolution, high signal-to-noise spectra of the Calcium triplet absorption lines on the photometric axes of the stellar spheroid in the polar disk galaxy NGC4650A. Along the major axis, the observed rotation and velocity dispersion measurements show the presence of a kinematically decoupled nucleus, and a flat velocity dispersion profile. The minor axis kinematics is determined for the first time: along this direction some rotation is measured, and the velocity dispersion is nearly constant and slightly increases at larger distances from the center. The new high resolution kinematic data suggest that the stellar component in NGC4650A resembles a nearly-exponential oblate spheroid supported by rotation. The main implications of these results on the previous mass models for NGC4650A are discussed. Moreover, the new kinematic data set constraints on current models for the formation scenarios of Polar Ring Galaxies (PRGs), supporting a slow accretion rather then a secondary strong dissipative event., Comment: 25 pages, 8 figures, accepted for publication in the Astrophysical Journal
Published: 2006
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11. AM 1934-563: A giant spiral polar-ring galaxy in a triplet

Author: Reshetnikov, V., Bournaud, F., Combes, F., Faundez-Abans, M., and de Oliveira-Abans, M.
Subjects: Astrophysics
Abstract: We have observed the emission-line kinematics and photometry of a southern triplet of galaxies. The triplet contains a giant spiral galaxy AM 1934-563 which optical structure resembles a polar-ring galaxy: distorted spiral disk, seen almost edge-on, and a faint large-scale (45 kpc in diameter) warped structure, inclined by 60^o-70^o with respect to the disk major axis. The triplet shows relatively small velocity dispersion (69 km/s) and a large crossing time (0.17 in units of the Hubble time). The disk of AM 1934-563 demonstrates optical colors typical for an early-type spirals, strong radial color gradient, and almost exponential surface brightness distribution with an exponential scale-length value of 3.1 kpc (R passband). The galaxy shows a maximum rotation velocity of about 200 km/s and it lies close to the Tully-Fisher relation for spiral galaxies. The suspected polar ring is faint (\mu(B) > 24) and strongly warped. Its total luminosity comprises (10-15)% of the total luminosity of AM 1934-563. We then try to model this system using numerical simulations, and study its possible formation mechanisms. We find that the most robust model, that reproduces the observed characteristics of the ring and the host galaxy, is the tidal transfer of mass from a massive gas-rich donor galaxy to the polar ring. The physical properties of the triplet of galaxies are in agreement with this scenario., Comment: Accepted for publication in A&A
Published: 2005
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12. The life-time of galactic bars: central mass concentrations and gravity torques

Author: Bournaud, F., Combes, F., and Semelin, B.
Subjects: Astrophysics
Abstract: Bars in gas-rich spiral galaxies are short-lived. They drive gas inflows through their gravity torques, and at the same time self-regulate their strength. Their robustness has been subject of debate, since it was thought that only the resulting central mass concentrations (CMCs) were weakening bars, and only relatively rare massive CMCs were able to completely destroy them. Through numerical simulations including gas dynamics, we find that with the gas parameters of normal spiral galaxies, the CMC is not sufficient to fully dissolve the bar. But another overlooked mechanism, the transfer of angular momentum from the infalling gas to the stellar bar, can also strongly weaken the bar. In addition, we show that gravity torques are correctly reproduced in simulations, and conclude that bars are transient features, with life-time of 1-2 Gyr in typical Sb-Sc galaxies, because of the combined effects of CMCs and gravity torques, while most existing works had focussed on the CMC effects alone., Comment: accepted for publication in MNRAS. The definitive version is available at www.blackwell-synergy.com
Published: 2005
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13. Lopsided spiral galaxies: evidence for gas accretion

Author: Bournaud, F., Combes, F., Jog, C. J., and Puerari, I.
Subjects: Astrophysics
Abstract: We quantify the degree of lopsidedness for a sample of 149 galaxies observed in the near-infrared from the OSUBGS sample, and try to explain the physical origin for the observed disk lopsidedness. We confirm previous studies, but now for a larger sample, that a large fraction of galaxies show significant lopsidedness in their stellar disks, measured as the Fourier amplitude of the m=1 component, normalised to the average or m=0 component, in the surface density. Late-type galaxies are found to be more lopsided, while the presence of m=2 spiral arms and bars is correlated. The m=1 amplitude is found to be uncorrelated with the tidal forces acting on a galaxy via nearby companions. Numerical simulations are carried out to study the generation of m=1 via different processes: galaxy tidal encounters, galaxy mergers, and external gas accretion and subsequent star formation. The simulations show that galaxy interactions and mergers can trigger strong lopsidedness, but do not explain several independent statistical properties of observed galaxies. To explain all the observational results, it is required that a large fraction of lopsidedness results from cosmological accretion of gas on galactic disks, which can create strongly lopsided disks when this accretion is asymmetrical enough., Comment: accepted for publication in Astronomy and Astrophysics - Final version after language edition
Published: 2005
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14. Galaxy mergers with various mass ratios: properties of remnants

Author: Bournaud, F., Jog, C. J., and Combes, F.
Subjects: Astrophysics
Abstract: We study galaxy mergers with various mass ratios using N-body simulations, with an emphasis on the unequal-mass mergers in the relatively unexplored range of mass-ratios 4:1-10:1. Our recent work (Bournaud et al. 2004) shows that the above range of mass ratio results in hybrid systems with spiral-like luminosity profiles but with elliptical-like kinematics, as observed in the data analysis for a sample of mergers by Jog & Chitre (2002). In this paper, we study the merger-remnants for mass ratios from 1:1 to 10:1 while systematically covering the parameter space. We obtain the morphological and kinematical properties of the remnants, and also discuss the robustness and the visibility of disks in the merger remnants with a random line-of-sight. We show that the mass ratios 1:1-3:1 give rise to elliptical remnants whereas the mass ratios 4.5:1-10:1 produce the hybrid systems with mixed properties. We find that the transition between disk-like and elliptical remnants occurs between a narrow mass-range of 4.5:1-3:1. The unequal-mass mergers are more likely to occur than the standard equal-mass mergers studied in the literature so far, and we discuss their implications for the evolution of galaxies., Comment: Accepted for publication in Astronomy and Astrophysics - final version after language edition
Published: 2005
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15. Galaxy transmutations: The double ringed galaxy ESO 474-G26

Author: Reshetnikov, V., Bournaud, F., Combes, F., Faundez-Abans, M., de Oliveira-Abans, M., van Driel, W., and Schneider, S. E.
Subjects: Astrophysics
Abstract: Surface photometry and a 21cm HI line spectrum of the giant double-ringed galaxy ESO 474-G26 are presented. The morphology of this system is unique among the 30,000 galaxies with >B15. Two almost orthogonal optical rings with diameters of 60 and 40 kpc surround the central body (assuming H0=70 km/s/Mpc). The outer one is an equatorial ring, while the inner ring lies in a nearly polar plane. The rings have blue optical colors typical of late-type spirals. Both appear to be rotating around the central galaxy, so that this system can be considered as a kinematically confirmed polar ring galaxy. Its observational characteristics are typical of galaxy merger remnants. Although the central object has a surface brightness distribution typical of elliptical galaxies, it has a higher surface brightness for its effective radius than ordinary ellipticals. Possible origins of this galaxy are discussed and numerical simulations are presented that illustrate the formation of the two rings in the merging process of two spiral galaxies, in which the observed appearance of ESO 474-G26 appears to be a transient stage., Comment: Accepted for publication in A&A
Published: 2004
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16. Kinematics of tidal tails in interacting galaxies: Tidal Dwarf Galaxies and projection effects

Author: Bournaud, F., Duc, P. -A., Amram, P., Combes, F., and gach, J. L.
Subjects: Astrophysics
Abstract: The kinematics of tidal tails in colliding galaxies has been studied via Fabry-Perot observations of the Halpha emission. With their large field of view and high spatial resolution, the Fabry-Perot data allow to probe simultaneously, in 2-D, two kinematical features of the tidal ionized gas: large-scale velocity gradients due to streaming motions along the tails, and small-scale motions related to the internal dynamics of giant HII regions within the tails. In several interacting systems, massive (10^9 Msun) condensations of HI, CO and stars are observed in the outer regions of tails. Whether they are genuine accumulations of matter or not is still debated. Indeed a part of the tidal tail may be aligned with the line-of-sight, and the associated projection effect may result in apparent accumulations of matter that does not exist in the 3-D space. Using numerical simulations, we show that studying the large-scale kinematics of tails, it is possible to know whether these accumulations of matter are the result of projection effects or not. We conclude that several ones are genuine accumulations of matter. We also study the small-scale motions inside these regions: several small-scale velocity gradients are identified with projected values as large as 50-100 km/s accross the observed HII regions. In one system, the spatial resolution of our observations is sufficient to detail the velocity field; we show that it is rotating and self-gravitating, and discuss its dark matter content. The Fabry-Perot observations have thus enabled us to prove that some 10^9 Msun condensations of matter are real structures, and are kinematically decoupled from the rest of the tail. Such massive and self-gravitating objects are the progenitors of the so-called ''Tidal Dwarf Galaxies''., Comment: 16 pages, 20 figures, A&A in press. Full accepted version with appendix and color pictures available at: http://alpha.uni-sw.gwdg.de/~paduc/articles/FP.pdf - Table A1 revised - final version after language editing
Published: 2004
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17. Halpha Kinematics of Tidal Tails in Interacting Systems: Projection Effects and Dark Matter in TDGs

Author: Amram, P., Bournaud, F., and Duc, P. -A.
Subjects: Astrophysics
Abstract: Several interacting systems exhibit at the tip of their long tidal tails massive condensations of atomic hydrogen, which may be the progenitors of Tidal Dwarf Galaxies. Because, quite often, these tails are observed edge-on, projection effects have been claimed to account for the large HI column densities measured there. Here we show that determining the velocity field all along the tidal features, one may disentangle projection effects along the line of view from real bound structures. Due to its large field of view, high spectral and 2D spatial resolutions, Fabry-Perot observations of the ionized gas are well adapted to detect a kinematical signature of either streaming motions along a bent tidal tail or of infalling/rotating material associated with a forming TDG. Spectroscopic observations also allow to measure the dynamical masses of the TDGs that are already relaxed and check their dark matter content., Comment: 6 pages, 5 figures. IAU Symposium 217
Published: 2004

18. ce-61: a Tidal Dwarf Galaxy in the Hercules cluster?

Author: van Driel, W., Duc, P. -A., Amram, P., Bournaud, F., Balkowski, C., Cayatte, V., Dickey, J., Hernandez, H., Iglesias-Paramo, J., O'Neil, K., Papaderos, P., and Vilchez, J. M.
Subjects: Astrophysics
Abstract: A candidate Tidal Dwarf Galaxy, ce-61, was identified in the merger system IC 1182 in the Hercules supercluster. The multi-wavelength data we obtained so far do not prove, however, that it is kinematically detached from the IC 1182 system and gravitationally bound., Comment: Proc. of IAU Symp. 217 on Recycling Intergalactic and Interstellar Matter, 2 pages
Published: 2003

19. The large extent of dark matter haloes probed by the formation of tidal dwarf galaxies

Author: Bournaud, F., Duc, P. -A., and Masset, F.
Subjects: Astrophysics
Abstract: In several interacting systems, gas accumulations as massive as 10^9 solar masses are observed near the tip of tidal tails, and are thought to be possible progenitors of Tidal Dwarf Galaxies. Using N-body simulations of galaxy interactions, we show that the existence of such features requires that dark matter haloes around spiral galaxies extend at least ten times further than the stellar disks. The massive gas clouds formed in our simulations have a kinematical origin and gravitationally collapse into dwarf galaxies that often survive for a few billion years., Comment: Accepted for publication in A&A 4 pages, 3 figures
Published: 2003
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20. Formation of polar ring galaxies

Author: Bournaud, F. and Combes, F.
Subjects: Astrophysics
Abstract: Polar ring galaxies are peculiar systems in which a gas rich, nearly polar ring surrounds an early-type or elliptical host galaxy. Two formation scenarios for these objects have been proposed: they are thought to form either in major galaxy mergers or by tidal accretion of the polar material from a gas rich donor galaxy. Both scenarios are studied through N-body simulations including gas dynamics and star formation. Constraints on physical parameters are drawn out, in order to determine which scenario is the most likely to occur. Polar ring galaxies from each scenario are compared with observations and we discuss whether the accretion scenario and the merging scenario account for observational properties of polar ring galaxies. The conclusion of this study is that the accretion scenario is both the most likely and the most supported by observations. Even if the merging scenario is rather robust, most polar ring galaxies are shown to be the result of tidal gas accretion events., Comment: Accepted for publication in A&A. 20 pages, 14 figures. The resolution of several figures has been reduced in this version
Published: 2003
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21. Polar Ring Galaxies and the Tully Fisher relation: implications for the dark halo shape

Author: Iodice, E., Arnaboldi, M., Bournaud, F., Combes, F., Sparke, L. S., van Driel, W., and Capaccioli, M.
Subjects: Astrophysics
Abstract: We have investigated the Tully-Fisher relation for Polar Ring Galaxies (PRGs), based on near infrared, optical and HI data available for a sample of these peculiar objects. The total K-band luminosity, which mainly comes from the central host galaxy, and the measured HI linewidth at 20% of the peak line flux density, which traces the potential in the polar plane, place most polar rings of the sample far from the Tully-Fisher relation defined for spiral galaxies, with many PRGs showing larger HI linewidths than expected for the observed K band luminosity. This result is confirmed by a larger sample of objects, based on B-band data. This observational evidence may be related to the dark halo shape and orientation in these systems, which we study by numerical modeling of PRG formation and dynamics: the larger rotation velocities observed in PRGs can be explained by a flattened polar halo, aligned with the polar ring., Comment: 22 pages, 8 postscript figures, accepted for publication in Astrophysical Journal
Published: 2002
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22. Gas accretion on spiral galaxies: bar formation and renewal

Author: Bournaud, F. and Combes, F.
Subjects: Astrophysics
Abstract: The effects of gas accretion on spiral disk dynamics and stability are studied through N-body simulations, including star formation and gas/stars mass exchange. The detailed processes of bar formation, bar destruction and bar re-formation are followed, while in the same time the disk to bulge ratio is varying. The accreted gas might be first prevented to flow inwards to the center by the bar gravity torques, which maintains it to the outer Lindblad resonance. While the first bar is weakening, the accreted gas replenishes the disk, increasing the disk-to-bulge ratio, and the disk self-gravity. A second bar is then unstable, with a higher pattern speed, due both to the increased mass, and shorter bar length. Three or four bar episodes have been followed over a Hubble time. Their strength is decreasing with time, while their pattern speed is increasing. Detailed balance of the angular momentum transfer and evolution can account for these processes. The gas recycled through star formation, and rejected through stellar mass loss plays also a role in the disk dynamics. Implications on the spiral galaxy dynamics and evolution along the Hubble sequence, and as a function of redshift are discussed., Comment: 21 pages, 21 figures. Accepted for publication in A&A. Figs. 1, 2, 5, 10, 14, 15, 19 are available as jpeg files
Published: 2002
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23. GOODS-ALMA 2.0: Source catalog, number counts, and prevailing compact sizes in 1.1 mm galaxies

Author: Gómez-Guijarro, C., Elbaz, D., Xiao, M., Béthermin, M., Franco, M., Magnelli, B., Daddi, E., Dickinson, M., Demarco, R., Inami, H., Rujopakarn, W., Magdis, G.E., Shu, X., Chary, R., Zhou, L., Alexander, D.M., Bournaud, F., Ciesla, L., Ferguson, H.C., Finkelstein, S.L., Finlez, C., Giavalisco, M., Iono, D., Juneau, S., Kartaltepe, J.S., Lagache, G., Le Floc'H, E., Leiton, R., Lin, L., Messias, H., Motohara, K., Mullaney, J., Nagar, N.M., Okumura, K., Pannella, M., Papovich, C., Pope, A., Sargent, M.T., Silverman, J.D., Treister, E., Wang, T., Le Floc’h, E., Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Hertfordshire [Hatfield] (UH), NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), Universidad de Concepción - University of Concepcion [Chile], Hiroshima University, Chulalongkorn University [Bangkok], Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Anhui Normal University, California Institute of Technology (CALTECH), Nanjing University (NJU), Durham University, Space Telescope Science Institute (STSci), University of Texas at Austin [Austin], University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS), National Astronomical Observatory of Japan (NAOJ), Rochester Institute of Technology, Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Academia Sinica, The University of Tokyo (UTokyo), University of Sheffield [Sheffield], Università degli studi di Trieste = University of Trieste, Texas A&M University System, University of Sussex, Pontificia Universidad Católica de Chile (UC), Univ New South Wales, MERLin Sch Chem Engn, Sydney, NSW 2052, Australia, and We thank G. Pöpping, C. del P. Lagos, and J. A.Zavala for providing the predicted number counts from their models plotted in Fig. 11. M.F. acknowledges the support from STFC (grant number ST/R000905/1). G.E.M. acknowledges the Villum Fonden research grant 13160 ‘Gas to stars, stars to dust: tracing star formation across cosmic time’ and the Cosmic Dawn Center of Excellence funded by the Danish National Research Foundation under the grant No. 140. H.I. acknowledges support from JSPS KAKENHI Grant Number JP19K23462 and JP21H01129. M.T.S. acknowledges support from a Scientific Exchanges visitor fellowship (IZSEZO_202357) from the Swiss National Science Foundation. This papermakes use of the following ALMA data: ADS/JAO.ALMA#2015.1.00543.S and ADS/JAO.ALMA#2017.1.00755.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. We are grateful to the anonymous referee, whose comments have been very useful to improving our work
Subjects: submillimeter: galaxies, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Stellar mass, structure [Galaxies], PHYSICAL-PROPERTIES, FOS: Physical sciences, Flux, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, star formation [Galaxies], 01 natural sciences, GMASS ULTRADEEP SPECTROSCOPY, high-redshift [Galaxies], galaxies [Submillimeter], galaxies: high-redshift, 0103 physical sciences, STAR-FORMING GALAXIES, Sensitivity (control systems), Continuum (set theory), DEEP FIELD-SOUTH, MAIN-SEQUENCE, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Effective radius, Physics, DEGREE EXTRAGALACTIC SURVEY, SUBMILLIMETER GALAXIES, 010308 nuclear & particles physics, photometry [Galaxies], Homogeneity (statistics), MASSIVE GALAXIES, Astronomy and Astrophysics, evolution [Galaxies], FAR-INFRARED PROPERTIES, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, galaxies: photometry, LUMINOSITY FUNCTION, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: star formation, galaxies: structure, Astrophysics::Earth and Planetary Astrophysics, galaxies: evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Submillimeter/millimeter observations of dusty star-forming galaxies with the Atacama Large Millimeter/submillimeter Array (ALMA) have shown that dust continuum emission generally occurs in compact regions smaller than the stellar distribution. However, it remains to be understood how systematic these findings are. Studies often lack homogeneity in the sample selection, target discontinuous areas with inhomogeneous sensitivities, and suffer from modest $uv$ coverage coming from single array configurations. GOODS-ALMA is a 1.1mm galaxy survey over a continuous area of 72.42arcmin$^2$ at a homogeneous sensitivity. In this version 2.0, we present a new low resolution dataset and its combination with the previous high resolution dataset from the survey, improving the $uv$ coverage and sensitivity reaching an average of $��= 68.4��$Jy beam$^{-1}$. A total of 88 galaxies are detected in a blind search (compared to 35 in the high resolution dataset alone), 50% at $S/N_{peak} \geq 5$ and 50% at $3.5 \leq S/N_{peak} \leq 5$ aided by priors. Among them, 13 out of the 88 are optically dark or faint sources ($H$- or $K$-band dropouts). The sample dust continuum sizes at 1.1mm are generally compact, with a median effective radius of $R_{e} = 0"10 \pm 0"05$ (a physical size of $R_{e} = 0.73 \pm 0.29$kpc at the redshift of each source). Dust continuum sizes evolve with redshift and stellar mass resembling the trends of the stellar sizes measured at optical wavelengths, albeit a lower normalization compared to those of late-type galaxies. We conclude that for sources with flux densities $S_{1.1mm} > 1$mJy, compact dust continuum emission at 1.1mm prevails, and sizes as extended as typical star-forming stellar disks are rare. The $S_{1.1mm} < 1$mJy sources appear slightly more extended at 1.1mm, although they are still generally compact below the sizes of typical star-forming stellar disks., Accepted by A&A. 30 pages, 18 figures
Published: 2022

24. The [C ii] emission as a molecular gas mass tracer in galaxies at low and high redshifts

Author: Zanella, A., Daddi, Emanuele, Magdis, G., Diaz Santos, T., Cormier, D., Liu, D., Cibinel, A., Gobat, R., Dickinson, M., Sargent, M., Popping, G., Madden, S. C., Béthermin, M., Hughes, T. M., Valentino, F., Rujopakarn, W., Pannella, M., Bournaud, F., Walter, F., Wang, T., Elbaz, D., Coogan, R. T., Daddi, A, Diaz santos, A, Cormier, A, Liu, A, Gobat, A, Dickinson, A, Sargent, A, Popping, A., Madden, A, Bethermin, A, Hughes, A, Valentino, D, Rujopakarn, A, Pannella, G, Bournaud, A, Walter, A., Wang, A, Elbaz, A., Coogan, A, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), National Optical Astronomy Observatory (NOAO), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Sterrenkundig Observatorium, Universiteit Gent = Ghent University (UGENT), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, University of Strathclyde [Glasgow], Faculté de pharmacie, Université Louis Pasteur - Strasbourg I, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), NOAO, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Universiteit Gent, and University of Strathclyde
Subjects: galaxies: high redshift, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Metallicity, FOS: Physical sciences, galaxies: starburst, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Computer Science::Computational Geometry, 01 natural sciences, Luminosity, TRACER, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, QB, Physics, 010308 nuclear & particles physics, Star formation, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, Interstellar medium, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: star formation, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Spatial extent, galaxies: evolution, submillimetre: galaxies, galaxies: ISM
Abstract: We present ALMA Band 9 observations of the [C II]158um emission for a sample of 10 main-sequence galaxies at redshift z ~ 2, with typical stellar masses (log M*/Msun ~ 10.0 - 10.9) and star formation rates (~ 35 - 115 Msun/yr). Given the strong and well understood evolution of the interstellar medium from the present to z = 2, we investigate the behaviour of the [C II] emission and empirically identify its primary driver. We detect [C II] from six galaxies (four secure, two tentative) and estimate ensemble averages including non detections. The [C II]-to-infrared luminosity ratio (L[C II]/LIR) of our sample is similar to that of local main-sequence galaxies (~ 2 x 10^-3), and ~ 10 times higher than that of starbursts. The [C II] emission has an average spatial extent of 4 - 7 kpc, consistent with the optical size. Complementing our sample with literature data, we find that the [C II] luminosity correlates with galaxies' molecular gas mass, with a mean absolute deviation of 0.2 dex and without evident systematics: the [C II]-to-H2 conversion factor (alpha_[C II] ~ 30 Msun/Lsun) is largely independent of galaxies' depletion time, metallicity, and redshift. [C II] seems therefore a convenient tracer to estimate galaxies' molecular gas content regardless of their starburst or main-sequence nature, and extending to metal-poor galaxies at low and high redshifts. The dearth of [C II] emission reported for z > 6 - 7 galaxies might suggest either a high star formation efficiency or a small fraction of UV light from star formation reprocessed by dust., Accepted for publication in MNRAS. 28 pages, including 12 figures, 5 tables, 3 appendices
Published: 2018

25. The Dust and [C ii] Morphologies of Redshift ∼4.5 Sub-millimeter Galaxies at ∼200 pc Resolution:The Absence of Large Clumps in the Interstellar Medium at High-redshift

Author: Novak, Mladen, Sargent, Mark, Herrera-Camus, R., Belli, S., Übler, H., Shimizu, T., Davies, R., Sturm, E., Colina, L., Cunha, E. da, Rybak, M., Venemans, B., Brandt, W., Rivera, G. Calistro, Knudsen, K., Werf, P. van der, Freundlich, J., Combes, F., Tacconi, L., Genzel, R., Garcia-Burillo, S., Bolatto, A., Lilly, S., Salomé, P., Bicalho, I., Boissier, J., Boone, F., Bouché, N., Bournaud, F., Burkert, A., Carollo, M., Cooper, M., Feruglio, C., Förster Schreiber, N., Juneau, S., Lippa, M., Lutz, D., Naab, T., Renzini, A., Saintonge, A., Sternberg, A., Weiner, B., Weiß, A., Wuyts, S., Bouwens, Rychard, Brinchmann, Jarle, Maseda, Michael, Matthee, Jorryt, Schaye, Joop, Schouws, Sander, Pavesi, Riccardo, Le Fèvre, Olivier, Yang, C., Gavazzi, R., Beelen, A., Lehnert, M., Gao, Y., Barcos-Muñoz, L., Neri, R., Fu, H., González-Alfonso, E., Michałowski, M., Nightingale, J., Pérez-Fournon, I., Shao, Yali, Wang, Ran, Li, Jianan, Fan, Xiaohui, Jiang, Linhua, Strauss, Michael, Menten, Karl, Ma, Jingzhe, Cooray, Asantha, Nayyeri, Hooshang, Brown, Arianna, Ghotbi, Noah, Oteo, Ivan, Duivenvoorden, Steven, Greenslade, Joshua, Clements, David, Battisti, Andrew, Ashby, Matthew, Perez-Fournon, Ismael, Oliver, Seb, Eales, Stephen, Negrello, Mattia, Dye, Simon, Dunne, Loretta, Omont, Alain, Serjeant, Stephen, Maddox, Steve, Valiante, Elisabetta, Pillepich, Annalisa, Nelson, Dylan, Cunha, Elisabete da, Diemer, Benedikt, González-López, Jorge, Hernquist, Lars, Marinacci, Federico, Rix, Hans-Walter, Swinbank, Mark, Vogelsberger, Mark, Werf, Paul van der, Yung, L., Aravena, Manuel, Decarli, Roberto, Gónzalez-López, Jorge, Boogaard, Leindert, Carilli, Chris, Popping, Gergö, Assef, Roberto, Bacon, Roland, Bauer, Franz Erik, Bouwens, Richard, Contini, Thierry, Cortes, Paulo, Da Cunha, Elisabete, Daddi, Emanuele, Díaz-Santos, Tanio, Elbaz, David, Inami, Hanae, Fevre, Olivier Le, Magnelli, Benjamin, Oesch, Pascal, Riechers, Dominik, Somerville, Rachel, Uzgil, Bade, Wagg, Jeff, Wisotzki, Lutz, Gullberg, B., Swinbank, A. Mark, Smail, Ian, Biggs, A., Bertoldi, Frank, Breuck, C. De, Chapman, S., Chen, Chian-Chou, Cooke, E., Coppin, K., Cox, Pierre, Dannerbauer, H., Dunlop, J., Edge, A., Farrah, D., Geach, J., GREVE, T., Hodge, Jacqueline, Ibar, E., Ivison, Rob, Karim, A., Schinnerer, E., Scott, Douglas, Simpson, J., Stach, S., Thomson, A., Van Der Werf, Paul, Walter, Fabian, Wardlow, Julie, Weiss, Axel, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Department of Physics, Durham University, Racah Institute of Physics, The Hebrew University of Jerusalem (HUJ), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Observatorio Astronomico Nacional [Madrid] (OAN), Instituto Geografico Nacional (IGN), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, AUTRES, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke [Sherbrooke], Universitätssternwarte der Ludwig-Maximiliansuniversität, Ludwig-Maximiliansuniversität, Institute for Astronomy [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), University of São Paulo, INAF - Osservatorio Astronomico di Roma (OAR), Istituto Nazionale di Astrofisica (INAF), Steward observatory, University of Arizona, Max-Planck-Institut für Extraterrestrische Physik (MPE), Institut of Physics - Riga, Latvian Academy of Sciences, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Guangzhou Marine Geological Survey, Ministry of Land and Resources (MLR), Physics Department [Santa Barbara], University of California [Santa Barbara] (UCSB), University of California-University of California, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL), Milieux aquatiques, écologie et pollutions (UR MALY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Universidad de Alcalá - University of Alcalá (UAH), Instituto de Astrofisica de Canarias (IAC), Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Arizona State University [Tempe] (ASU), Max-Planck-Institut für Radioastronomie (MPIFR), California Institute of Technology (CALTECH), Astronomy Centre, University of Sussex, University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS), School of Physics and Astronomy [Cardiff], Cardiff University, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires de Marseille (ISM2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), School of Physics and Astronomy [Nottingham], University of Nottingham, UK (UON), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Max-Planck-Institut für Astronomie (MPIA), Institute for Computational Cosmology (ICC), National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Yale Center for Astronomy and Astrophysics (YCAA), Yale University [New Haven], Cornell University, Rutgers University, Astrophysikalisches Institut Potsdam (AIP), Institute of Computational Cosmology, Argelander Institute for Astronomy (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Université de Lyon, SUPA, Institute for Astronomy, University of Edinburgh, University of Wales, Department of Physics [Blacksburg], Virginia Tech [Blacksburg], Space Plasma Group, Astronomy Unit [London] (AU), Queen Mary University of London (QMUL)-Queen Mary University of London (QMUL), Royal Observatory Edinburgh (ROE), Interactions et dynamique des environnements de surface (IDES), CLRC Daresbury, SFTC, Centre de Recherches sur la Cognition Animale (CRCA), Institut des sciences du cerveau de Toulouse. (ISCT), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Pacific Northwest National Laboratory (PNNL), Department of Astronomy, University of California [Irvine] (UCI), Centre de Biologie Intégrative (CBI), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut des sciences du cerveau de Toulouse. (ISCT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), FOS: Physical sciences, galaxies [submillimeter], Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, evolution [galaxies], Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], ISM [galaxies], 010308 nuclear & particles physics, Resolution (electron density), Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Redshift, Galaxy, Interstellar medium, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), Millimeter, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present deep high resolution (0.03", 200pc) ALMA Band 7 observations covering the dust continuum and [CII] $\lambda157.7\mu$m emission in four $z\sim4.4-4.8$ sub-millimeter galaxies (SMGs) selected from the ALESS and AS2UDS surveys. The data show that the rest-frame 160$\mu$m (observed 345 GHz) dust emission is consistent with smooth morphologies on kpc scales for three of the sources. One source, UDS47.0, displays apparent substructure but this is also consistent with a smooth morphology, as indicated by simulations showing that smooth exponential disks can appear clumpy when observed at high angular resolution (0.03") and depth of these observations ($\sigma_{345\text{GHz}} \sim27-47\mu$Jy beam$^{-1}$). The four SMGs are bright [CII] emitters, and we extract [CII] spectra from the high resolution data, and recover $\sim20-100$% of the [CII] flux and $\sim40-80$% of the dust continuum emission, compared to the previous lower resolution observations. When tapered to 0.2" resolution our maps recover $\sim80-100$% of the continuum emission, indicating that $\sim60$% of the emission is resolved out on $\sim200$pc scales. We find that the [CII] emission in high-redshift galaxies is more spatially extended than the rest-frame 160$\mu$m dust continuum by a factor of $1.6\pm0.4$. By considering the $L_{\text{[CII]}}$/$L_{\text{FIR}}$ ratio as a function of the star-formation rate surface density ($\Sigma_{\text{SFR}}$) we revisit the [CII] deficit, and suggest that the decline in the $L_{\text{[CII]}}$/$L_{\text{FIR}}$ ratio as a function of $\Sigma_{\text{SFR}}$ is consistent with local processes. We also explore the physical drivers that may be responsible for these trends and can give rise to the properties found in the densest regions of SMGs., Comment: 15 pages, 6 figures, 4 tables, accepted for publication in ApJ
Published: 2018

26. Quenching of Star Formation in Molecular Outflow Host NGC 1266

Author: Alatalo, K., Nyland, K. E., Graves, G., Deustua, S., Young, L. M., Davis, T. A., Crocker, A. F., Bureau, M., Bayet, E., Blitz, L., Bois, M., Bournaud, F., Cappellari, M., Davies, R. L., de Zeeuw, P. T., Emsellem, E., Khochfar, S., Krajnovic, D., Kuntschner, H., McDermid, R. M., Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A., Wong, Tony, Ott, Jürgen, and Astronomy
Subjects: Physics, Quenching, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Stellar population, Star formation, galaxies: active, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Galaxy, Stars, Space and Planetary Science, galaxies: individual (NGC 1266), Outflow, galaxies: evolution, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We detail the rich molecular story of NGC 1266, its serendipitous discovery within the ATLAS3D survey (Cappellari et al. 2011) and how it plays host to an AGN-driven molecular outflow, potentially quenching all of its star formation (SF) within the next 100 Myr. While major mergers appear to play a role in instigating outflows in other systems, deep imaging of NGC 1266 as well as stellar kinematic observations from SAURON, have failed to provide evidence that NGC 1266 has recently been involved in a major interaction. The molecular gas and the instantaneous SF tracers indicate that the current sites of star formation are located in a hypercompact disk within 200 pc of the nucleus (Fig. 1; SF rate ~ 2 Msuns/yr). On the other hand, tracers of recent star formation, such as the H{\beta} absorption map from SAURON and stellar population analysis show that the young stars are distributed throughout a larger area of the galaxy than current star formation. As the AGN at the center of NGC 1266 continues to drive cold gas out of the galaxy, we expect star formation rates to decline as the star formation is ultimately quenched. Thus, NGC 1266 is in the midst of a key portion of its evolution and continued studies of this unique galaxy may help improve our understanding of how galaxies transition from the blue to the red sequence (Alatalo et al. 2011)., Comment: 1 page, Proceedings IAU symposium No. 292: Molecular gas, dust and star formation in galaxies, ed. by Tony Wong and Juergen Ott
Published: 2013

27. Probing the mass assembly of massive nearby galaxies with deep imaging

Author: Duc, P. -A, Cuillandre, J. -C, Alatalo, K., Blitz, L., Bois, M., Bournaud, F., Bureau, M., Cappellari, M., Côté, P., Davies, R. L., Davis, T. A., de Zeeuw, P. T., Emsellem, E., Ferrarese, L., Ferriere, E., Gwyn, S., Khochfar, S., Krajnovic, D., Kuntschner, H., Lablanche, P. -Y, McDermid, R. M., Michel-Dansac, L., Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A., Young, L. M., Thomas, Daniel, Pasquali, Anna, Ferreras, Ignacio, and Astronomy
Subjects: Physics, Effective radius, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Stellar mass, FOS: Physical sciences, Perturbation (astronomy), Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Redshift, Accretion (astrophysics), cD, Space and Planetary Science, galaxies: interactions, Astrophysics::Solar and Stellar Astrophysics, Surface brightness, Halo, Astrophysics::Earth and Planetary Astrophysics, galaxies: elliptical and lenticular, galaxies: evolution, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: According to a popular scenario supported by numerical models, the mass assembly and growth of massive galaxies, in particular the Early-Type Galaxies (ETGs), is, below a redshift of 1, mainly due to the accretion of multiple gas-poor satellites. In order to get observational evidence of the role played by minor dry mergers, we are obtaining extremely deep optical images of a complete volume limited sample of nearby ETGs. These observations, done with the CFHT as part of the ATLAS3D, NGVS and MATLAS projects, reach a stunning 28.5 - 29 mag.arcsec-2 surface brightness limit in the g' band. They allow us to detect the relics of past collisions such as faint stellar tidal tails as well as the very extended stellar halos which keep the memory of the last episodes of galactic accretion. Images and preliminary results from this on-going survey are presented, in particular a possible correlation between the fine structure index (which parametrizes the amount of tidal perturbation) of the ETGs, their stellar mass, effective radius and gas content., International Astronomical Union Symposium 295: The intriguing life of massive galaxies, August 27-31, 2012, Beijing, China
Published: 2012

28. Molecular Gas and Star Formation in Local Early-type Galaxies

Author: Bureau, M., Davis, T. A., Alatalo, K., Crocker, A. F., Blitz, L., Young, L. M., Combes, F., Bois, M., Bournaud, F., Cappellari, M., Davies, R. L., de Zeeuw, P. T., Duc, P. -A, Emsellem, E., Khochfar, S., Krajnović, D., Kuntschner, H., Lablanche, P. -Y, McDermid, R. M., Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A., Carignan, Claude, Combes, François, Freeman, Ken C., and Astronomy
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Field (physics), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, cD, Luminosity, ISM: evolution, Cluster (physics), galaxies: elliptical and lenticular, galaxies: kinematics and dynamics, Astrophysics::Galaxy Astrophysics, ISM: kinematics and dynamics, Physics, Star formation, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: molecules, Galaxy, Early type, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Detection rate, galaxies: evolution, galaxies: ISM, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The molecular gas content of local early-type galaxies is constrained and discussed in relation to their evolution. First, as part of the Atlas3D survey, we present the first complete, large (260 objects), volume-limited single-dish survey of CO in normal local early-type galaxies. We find a surprisingly high detection rate of 22%, independent of luminosity and at best weakly dependent on environment. Second, the extent of the molecular gas is constrained with CO synthesis imaging, and a variety of morphologies is revealed. The kinematics of the molecular gas and stars are often misaligned, implying an external gas origin in over a third of the systems, although this behaviour is drastically diffferent between field and cluster environments. Third, many objects appear to be in the process of forming regular kpc-size decoupled disks, and a star formation sequence can be sketched by piecing together multi-wavelength information on the molecular gas, current star formation, and young stars. Last, early-type galaxies do not seem to systematically obey all our usual prejudices regarding star formation, following the standard Schmidt-Kennicutt law but not the far infrared-radio correlation. This may suggest a greater diversity in star formation processes than observed in disk galaxies. Using multiple molecular tracers, we are thus starting to probe the physical conditions of the cold gas in early-types., Proceedings of the IAU Symposium 277 "Tracing the Ancestry of Galaxies". 4 pages, 3 figures
Published: 2011

29. Polar ring galaxies: formation and properties

Author: Bournaud, F., Francoise Combes, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), F. Combes and D. Barret, École normale supérieure - Paris (ENS Paris), and arXiv, Import
Subjects: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Mathematics::Commutative Algebra, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Formation scenarios for polar ring galaxies are studied through N-body simulatio ns that are compared with existing observations. It is shown that polar rings ar e likely to be formed by tidal accretion of the polar material from a gas rich d onor galaxy. The distribution of dark matter in polar ring galaxies is studied: dark halos seem to be flattened towards the polar rings., 2 pages, 1 figure, Proceedings SF2A-2002, Paris, ed. F. Combes and D. Barret, EDP-Sciences
Published: 2002

30. THE METALLICITY DEPENDENCE OF THE CO → H2 CONVERSION FACTOR IN z ≥ 1 STAR-FORMING GALAXIES.

Author: Genzel, R., Tacconi, L. J., Combes, F., Bolatto, A., Neri, R., Sternberg, A., Cooper, M. C., Bouchié, N., Bournaud, F., Burkert, A., Comerford, J., Cox, P., Davis, M., Schreiber, N. M. Förster, García-Burillo, S., Gracia-Carpio, J., Lutz, O., Naab, T., Newman, S., and Saintonge, A.
Subjects: GALAXY formation, ULTRAVIOLET radiation, REDSHIFT, STELLAR mass, ASTROPHYSICS
Abstract: We use the first systematic samples of CO millimeter emission in z ≥ 1 "main-sequence" star-forming galaxies to study the metallicity dependence of the conversion factor αCO, from CO line luminosity to molecular gas mass. The molecular gas depletion rate inferred from the ratio of the star formation rate (SFR) to CO luminosity, is ~1 Gyr-1 for near-solar metallicity galaxies with stellar masses above Ms ~ 101l M⊙. In this regime, the depletion rate does not vary more than a factor of two to three as a function of molecular gas surface density or redshift between z ~ 0 and 2. Below Ms the depletion rate increases rapidly with decreasing metallicity. We argue that this trend is not caused by starburst events, by changes in the physical parameters of the molecular clouds, or by the impact of the fundamental-metallicity-SFR-stellar mass relation. A more probable explanation is that the conversion factor is metallicity dependent and that star formation can occur in "CO-dark" gas. The trend is also expected theoretically from the effect of enhanced photodissociation of CO by ultraviolet radiation at low metallicity. From the available z ~ 0 and z ~ 1-3 samples we constrain the slope of the log(αCO)-log (metallicity) relation to range between -1 and -2, fairly insensitive to the assumed slope of the gas-SFR relation. Because of the lower metallicities near the peak of the galaxy formation activity at z ~ 1-2 compared to z ~ 0, we suggest that molecular gas masses estimated from CO luminosities have to be substantially corrected upward for galaxies below Ms. [ABSTRACT FROM AUTHOR]
Published: 2012
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31. An extremely young massive clump forming by gravitational collapse in a primordial galaxy

Author: Francesco Valentino, V. Perret, Masato Onodera, Emanuele Daddi, Anita Zanella, E. Le Floc'h, Raphael Gobat, Florent Renaud, V. Strazzullo, Anna Cibinel, Cristian Vignali, Frédéric Bournaud, Zanella, A, Daddi, E, Le Floc'h, E, Bournaud, F, Gobat, R, Valentino, F, Strazzullo, V, Cibinel, A, Onodera, M, Perret, V, Renaud, F, Vignali, C, Daddi, E., Le Floc'H, E., Bournaud, F., Gobat, R., Valentino, F., Strazzullo, V., Cibinel, A., Onodera, M., Perret, V., Renaud, F., Vignali, C., Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Ecosystèmes lagunaires : organisation biologique et fonctionnement (ECOLAG), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Ludwig-Maximilians-Universität München (LMU), Institute for Astronomy [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Istituto Nazionale di Astrofisica (INAF), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)
Subjects: Physics, Multidisciplinary, 010308 nuclear & particles physics, Star formation, FOS: Physical sciences, Astronomy, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Interstellar medium - Galaxies and clusters, Galaxy merger, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Billion years, Galaxy, Redshift, Gravitation, Stars, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Gravitational collapse, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: When the cosmic star formation history peaks (z ~ 2), galaxies vigorously fed by cosmic reservoirs are gas dominated and contain massive star-forming clumps, thought to form by violent gravitational instabilities in highly turbulent gas-rich disks. However, a clump formation event has not been witnessed yet, and it is debated whether clumps survive energetic feedback from young stars, thus migrating inwards to form galaxy bulges. Here we report spatially resolved spectroscopy of a bright off-nuclear emission line region in a galaxy at z = 1.987. Although this region dominates the star formation in the galaxy disk, its stellar continuum remains undetected in deep imaging, revealing an extremely young (age < 10 Myr) massive clump, forming through the gravitational collapse of > 10$^9$ M$_{\odot}$ of gas. Gas consumption in this young clump is > 10 times faster than in the host galaxy, displaying high star formation efficiency during this phase, in agreement with our hydrodynamic simulations. The frequency of older clumps with similar masses coupled with our initial estimate of their formation rate (~ 2.5 Gyr$^{-1}$) supports long lifetimes (~ 500 Myr), favouring scenarios where clumps survive feedback and grow the bulges of present-day galaxies., Published in May 7 issue of Nature (http://dx.doi.org/10.1038/nature14409)
Published: 2014

32. A titanic interstellar medium ejection from a massive starburst galaxy at redshift 1.4

Author: Emanuele Daddi, Annagrazia Puglisi, Frédéric Bournaud, A. Enia, Daizhong Liu, Shuowen Jin, Jeremy Fensch, Marcella Brusa, Michele Perna, Francesco Valentino, C. Circosta, A. Calabrò, Chiara Mancini, Ivan Delvecchio, Giulia Rodighiero, Puglisi A., Daddi E., Brusa M., Bournaud F., Fensch J., Liu D., Delvecchio I., Calabro A., Circosta C., Valentino F., Perna M., Jin S., Enia A., Mancini C., Rodighiero G., Delvecchio, I. [0000-0001-8706-2252], Enia, A. [0000-0002-0200-2857], Daddi, E. [0000-0002-3331-9590], Valentino, F. [0000-0001-6477-4011], Mancini, C. [0000-0002-4297-0561], Liu, D. [0000-0001-9773-7479], Science and Technology Facilities Council (STFC), European Regional Development Fund (ERDF), European Commission (EC), Comunidad de Madrid, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Active galactic nucleus, 010504 meteorology & atmospheric sciences, Galaxies and clusters, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Interstellar medium, Ionization, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Quenching, Star formation, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), Statistical Prevalence, galaxies, starburst, galaxy evolution
Abstract: Feedback-driven winds from star formation or active galactic nuclei might be a relevant channel for the abrupt quenching star formation in massive galaxies. However, both observations and simulations support the idea that these processes are non-conflictingly co-evolving and self-regulating. Furthermore, evidence of disruptive events that are capable of fast quenching is rare, and constraints on their statistical prevalence are lacking. Here we present a massive starburst galaxy at z=1.4 which is ejecting $46 \pm 13$\% of its molecular gas mass at a startling rate of $\gtrsim 10,000$ M$_{\odot}{\rm yr}^{-1}$. A broad component that is red-shifted from the galaxy emission is detected in four (low- and high-J) CO and [CI] transitions and in the ionized phase, which ensures a robust estimate of the expelled gas mass. The implied statistics suggest that similar events are potentially a major star-formation quenching channel. However, our observations provide compelling evidence that this is not a feedback-driven wind, but rather material from a merger that has been probably tidally ejected. This finding challenges some literature studies in which the role of feedback-driven winds might be overstated., Published in Nature Astronomy as an Article on 11 January 2021. The published version is available at https://www.nature.com/articles/s41550-020-01268-x (DOI 10.1038/s41550-020-01268-x)
Published: 2021

33. A contribution of star-forming clumps and accreting satellites to the mass assembly of z ∼ 2 galaxies

Author: Anna Cibinel, F. Valentino, Frederic Bournaud, Masato Onodera, A. Zanella, J. Sánchez Almeida, E. Le Floc'h, Raphael Gobat, E. Bernhard, Emanuele Daddi, Andreas Burkert, Christopher Harrison, Manuel Behrendt, Jakub Scholtz, Jérémy Fensch, V. Strazzullo, M. Kohandel, Zanella, A., Le Floc'h, E., Harrison, C. M., Daddi, E., Bernhard, E., Gobat, R., Strazzullo, V., Valentino, F., Cibinel, A., Sánchez Almeida, J., Kohandel, M., Fensch, J., Behrendt, M., Burkert, A., Onodera, M., Bournaud, F., and Scholtz, J.
Subjects: Stellar mass, FOS: Physical sciences, Astrophysics, interactions [Galaxies], Astrophysics::Cosmology and Extragalactic Astrophysics, irregular [galaxies], 01 natural sciences, law.invention, Telescope, law, 0103 physical sciences, galaxies: interactions, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, Spectroscopy, galaxies: irregular, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, evolution [galaxies], Physics, ISM [galaxies], 010308 nuclear & particles physics, Star formation, Spatially resolved, galaxies: evolution, galaxies: ISM, galaxies: star formation, galaxies: structure, Astrophysics - Astrophysics of Galaxies, Astronomy and Astrophysics, Mass ratio, Galaxy, interaction [galaxies], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), structure [galaxies], Astrophysics::Earth and Planetary Astrophysics, star formation [galaxies]
Abstract: We investigate the contribution of clumps and satellites to the galaxy mass assembly. We analyzed spatially-resolved Hubble Space Telescope observations (imaging and slitless spectroscopy) of 53 star-forming galaxies at z ~ 1 - 3. We created continuum and emission line maps and pinpointed residual "blobs" detected after subtracting the galaxy disk. Those were separated into compact (unresolved) and extended (resolved) components. Extended components have sizes ~ 2 kpc and comparable stellar mass and age as the galaxy disks, whereas the compact components are 1.5 dex less massive and 0.4 dex younger than the disks. Furthermore the extended blobs are typically found at larger distances from the galaxy barycenter than the compact ones. Prompted by these observations and by the comparison with simulations, we suggest that compact blobs are in-situ formed clumps, whereas the extended ones are accreting satellites. Clumps and satellites enclose respectively ~ 20% and ~< 80% of the galaxy stellar mass, ~ 30% and ~ 20% of its star formation rate. Considering the compact blobs, we statistically estimated that massive clumps (Mstar >~ 10^9 Msun) have lifetimes of ~ 650 Myr, and the less massive ones (10^8 < Mstar < 10^9 Msun) of ~ 145 Myr. This supports simulations predicting long-lived clumps (lifetime > 100 Myr). Finally, ~< 30% (13%) of our sample galaxies are undergoing single (multiple) merger(s), they have a projected separation ~< 10 kpc, and the typical mass ratio of our satellites is 1:5 (but ranges between 1:10 and 1:1), in agreement with literature results for close pair galaxies., 20 pages (plus appendix), 8 figures, 2 tables. Accepted for publication in MNRAS
Published: 2019

34. The unexpectedly large dust and gas content of quiescent galaxies at $z$ > 1.4

Author: M. S. Yun, Alvio Renzini, Georgios E. Magdis, Marie Martig, Grant W. Wilson, Itziar Aretxaga, Francesco Valentino, Veronica Strazzullo, Emanuele Daddi, R. Gobat, Ho Seong Hwang, Frédéric Bournaud, Alexis Finoguenov, Matthieu Béthermin, Mark Sargent, Shuowen Jin, School of Mathematics (KIAS Séoul), Korea Institute for Advanced Study (KIAS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), National Observatory of Athens (NOA), Dark Cosmology Centre (DARK), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Astronomy Centre, University of Sussex, Liverpool John Moores University (LJMU), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS), Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), Ludwig-Maximilians-Universität München (LMU), Gobat, R., Daddi, E., Magdis, G., Bournaud, F., Sargent, M., Martig, M., Jin, S., Finoguenov, A., Béthermin, M., Hwang, H. S., Renzini, A., Wilson, G. W., Aretxaga, I., Yun, M., Strazzullo, V., Valentino, F., Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Department of Physics
Subjects: COSMIC EVOLUTION, Active galactic nucleus, Stellar mass, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Milky Way, MU-M, POPULATION SYNTHESIS, RADIO PROPERTIES, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, GMASS ULTRADEEP SPECTROSCOPY, STAR-FORMATION, ELLIPTIC GALAXIES, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, QB, Physics, Spiral galaxy, 010308 nuclear & particles physics, Star formation, MASSIVE GALAXIES, Astronomy and Astrophysics, ATLAS(3D) PROJECT, 115 Astronomy, Space science, Astrophysics - Astrophysics of Galaxies, MOLECULAR GAS, Galaxy, Redshift, Interstellar medium, Astrophysics::Earth and Planetary Astrophysics, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA]
Abstract: Early type galaxies (ETG) contain most of the stars present in the local Universe and, above a stellar mass of ~5e10 Msun, vastly outnumber spiral galaxies like the Milky Way. These massive spheroidal galaxies have, in the present day, very little gas or dust, and their stellar populations have been evolving passively for over 10 billion years. The physical mechanisms that led to the termination of star formation in these galaxies and depletion of their interstellar medium remain largely conjectural. In particular, there are currently no direct measurements of the amount of residual gas that might be still present in newly quiescent spheroids at high redshift. Here we show that quiescent ETGs at z~1.8, close to their epoch of quenching, contained 2-3 orders of magnitude more dust at fixed stellar mass than local ETGs. This implies the presence of substantial amounts of gas (5-10%), which was however consumed less efficiently than in more active galaxies, probably due to their spheroidal morphology, and consistently with our simulations. This lower star formation efficiency, and an extended hot gas halo possibly maintained by persistent feedback from an active galactic nucleus (AGN), combine to keep ETGs mostly passive throughout cosmic time., Comment: 16 pages, 4 main figures main, 7 supplementary figures, 2 supplementary tables; accepted for publication in Nature Astronomy
Published: 2018

35. A giant Ly$\alpha$ nebula in the core of an X-ray cluster at $z=1.99$: implications for early energy injection

Author: Matthieu Béthermin, Mark Sargent, Francesco Valentino, Mark Dickinson, Alvio Renzini, Marcella Carollo, V. Strazzullo, Nobuo Arimoto, Cristian Vignali, Masato Onodera, David Elbaz, Raphael Gobat, Maurilio Pannella, Anita Zanella, Andrea Cimatti, Frédéric Bournaud, Amandine Le Brun, Alexis Finoguenov, Emanuele Daddi, Jean-Luc Starck, Valentino, Francesco, Daddi, Emanuele, Finoguenov, Alexi, Strazzullo, Veronica, Brun, Amandine Le, Vignali, Cristian, Bournaud, Frédéric, Dickinson, Mark, Renzini, Alvio, Béthermin, Matthieu, Zanella, Anita, Gobat, Raphaël, Cimatti, Andrea, Elbaz, David, Onodera, Masato, Pannella, Maurilio, Sargent, Mark, Arimoto, Nobuo, Carollo, Marcella, Starck, Jean-Luc, Valentino, F, Daddi, E, Finoguenov, A, Strazzullo, V, Le Brun, A, Vignali, C, Bournaud, F, Dickinson, M, Renzini, A, Bethermin, M, Zanella, A, Gobat, R, Cimatti, A, Elbaz, D, Onodera, M, Pannella, M, Sargent, M, Arimoto, N, Carollo, M, Starck, Jl, and Department of Physics
Subjects: ACTIVE GALACTIC NUCLEI, SIMILAR-TO 2, galaxies: clusters: intracluster medium, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Phase (waves), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, evolution [Galaxy], Luminosity, galaxies: high-redshift, BROAD-BAND SURVEY, Intracluster medium, 0103 physical sciences, STAR-FORMING GALAXIES, Cluster (physics), SINS/ZC-SINF SURVEY, COOLING FLOW, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, QB, Physics, Galaxy: evolution, Nebula, 010308 nuclear & particles physics, X-ray, Astronomy and Astrophysics, Astronomy and Astrophysic, 115 Astronomy, Space science, Astrophysics - Astrophysics of Galaxies, MOLECULAR GAS, Galaxy, clusters: individual (CL J1449+0856) [galaxies], Core (optical fiber), DARK-MATTER HALOES, clusters: intracluster medium [galaxies], Space and Planetary Science, galaxies: star formation, galaxies: clusters: individual (CL J1449+0856), active [galaxies], Astrophysics::Earth and Planetary Astrophysics, HIGH-REDSHIFT, star formation [galaxies], SKY SURVEY, high-redshift [galaxies], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present the discovery of a giant $\gtrsim$100~kpc Ly$\alpha$ nebula detected in the core of the X-ray emitting cluster CL~J1449+0856 at $z=1.99$ through Keck/LRIS narrow-band imaging. This detection extends the known relation between Ly$\alpha$ nebulae and overdense regions of the Universe to the dense core of a $5-7\times10^{13}$ M$_{\odot}$ cluster. The most plausible candidates to power the nebula are two Chandra-detected AGN host cluster members, while cooling from the X-ray phase and cosmological cold flows are disfavored primarily because of the high Ly$\alpha$ to X-ray luminosity ratio ($L_{\mathrm{Ly\alpha}}/L_{\mathrm{X}} \approx0.3$, $\gtrsim10-1000\times$ higher than in local cool-core clusters) and by current modeling. Given the physical conditions of the Ly$\alpha$-emitting gas and the possible interplay with the X-ray phase, we argue that the Ly$\alpha$ nebula would be short-lived ($\lesssim10$ Myr) if not continuously replenished with cold gas at a rate of $\gtrsim1000$ M$_{\odot}$ yr$^{-1}$. We investigate the possibility that cluster galaxies supply the required gas through outflows and we show that their total mass outflow rate matches the replenishment necessary to sustain the nebula. This scenario directly implies the extraction of energy from galaxies and its deposition in the surrounding intracluster medium, as required to explain the thermodynamic properties of local clusters. We estimate an energy injection of the order of $\thickapprox2$ keV per particle in the intracluster medium over a $2$ Gyr interval. In our baseline calculation AGN provide up to $85$% of the injected energy and 2/3 of the mass, while the rest is supplied by supernovae-driven winds., Comment: 15 pages, 11 figures, 1 appendix. Accepted for publication in ApJ
Published: 2016

36. METAL DEFICIENCY IN CLUSTER STAR-FORMING GALAXIES AT Z=2

Author: Nobuo Arimoto, Marcella Carollo, Stéphanie Juneau, Masato Onodera, Raphael Gobat, Emanuele Daddi, Frédéric Bournaud, Veronica Strazzullo, Alvio Renzini, Francesco Valentino, Anita Zanella, Valentino, F, Daddi, E, Strazzullo, V, Gobat, R, Onodera, M, Bournaud, F, Juneau, S, Renzini, A, Arimoto, N, Carollo, M, and Zanella, A
Subjects: Physics, Active galactic nucleus, 010308 nuclear & particles physics, Star formation, Metallicity, Doubly ionized oxygen, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, Star cluster, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Equivalent width, Galaxy cluster, Astrophysics::Galaxy Astrophysics
Abstract: We investigate the environmental effect on the metal enrichment of star-forming galaxies (SFGs) in the farthest spectroscopically confirmed and X-ray detected cluster, CL~J1449+0856 at $z=1.99$. We combined HST/WFC3~G141 slitless spectroscopic data, our 13-band photometry, and a recent Subaru/MOIRCS near infrared spectroscopic follow-up to constrain the physical properties of SFGs in CL~J1449+0856 and in a mass-matched field sample. After a conservative active galactic nuclei (AGN) removal, stacking individual MOIRCS spectra of $6$ ($31$) sources in the cluster (field) in the mass range $10 \leq \mathrm{log(M/M_{\odot}}) \leq 11$, we find a $\sim4\sigma$ significant lower [N II]/H$\alpha$ ratio in the cluster than in the field. Stacking a subsample of $16$ field galaxies with H$\beta$ and [O III] in the observed range, we measure a [O III]/H$\beta$ ratio fully compatible with the cluster value. Converting these ratios into metallicities, we find that the cluster SFGs are up to $0.25\,\mathrm{dex}$ poorer in metals than their field counterparts, depending on adopted calibrations. The low metallicity in cluster sources is confirmed using alternative indicators. Furthermore, we observe a significantly higher H$\alpha$ luminosity and equivalent width in the average cluster spectrum than in the field. This is likely due to enhanced specific star formation rate, even if lower dust reddening and/or an uncertain environmental dependence of the continuum-to-nebular emission differential reddening may play a role. Our findings might be explained by the accretion of pristine gas around galaxies at $z=2$ and from cluster-scale reservoirs, possibly connected with a phase of rapid halo mass assembly at $z>2$ and of high galaxy merging rate., Comment: 19 pages, 19 figures, 2 appendices, accepted by ApJ
Published: 2015

37. THE NEXT GENERATION VIRGO CLUSTER SURVEY-INFRARED (NGVS-IR). I. A NEW NEAR-ULTRAVIOLET, OPTICAL, AND NEAR-INFRARED GLOBULAR CLUSTER SELECTION TOOL

Author: Eric W. Peng, Matthew A. Taylor, Rossella Licitra, Michael L. Balogh, Andrés Jordán, Chengze Liu, Jean-Charles Cuillandre, Ariane Lançon, Laura Ferrarese, Stephen Gwyn, Thomas H. Puzia, Alan W. McConnachie, Chien Y. Peng, H. J. McCracken, Lauren A. MacArthur, R. Brent Tully, Patrick Côté, Marc Huertas-Company, Alessandro Boselli, Patrick R. Durrell, Stéphane Courteau, Frédéric Bournaud, Pierre-Alain Duc, Scott Chapman, Raymond G. Carlberg, Hongxin Zhang, Anand Raichoor, Simona Mei, Paul Eigenthaler, Roberto Munoz, Olivier Ilbert, Giuseppe Gavazzi, John P. Blakeslee, P. Hudelot, John L. Tonry, Ronald Läsker, Yannick Mellier, Eric Emsellem, Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Canada-France-Hawaii Telescope Corporation (CFHT), National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i [Honolulu] (UH), Services communs OMP (UMS 831), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Waterloo [Waterloo], Leiden Observatory [Leiden], Universiteit Leiden, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Dalhousie University [Halifax], Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB), Pontificia Universidad Católica de Chile (UC), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences [Changchun Branch] (CAS), Services communs OMP - UMS 831 (UMS 831), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Universiteit Leiden [Leiden], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Universitá degli Studi di Milano-Bicocca, Universitá degli Studi di Milan-Bocca, PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Muñoz, R, Puzia, T, Lançon, A, Peng, E, Côté, P, Ferrarese, L, Blakeslee, J, Mei, S, Cuillandre, J, Hudelot, P, Courteau, S, Duc, P, Balogh, M, Boselli, A, Bournaud, F, Carlberg, R, Chapman, S, Durrell, P, Eigenthaler, P, Emsellem, E, Gavazzi, G, Gwyn, S, Huertas Company, M, Ilbert, O, Jordán, A, Läsker, R, Licitra, R, Liu, C, Macarthur, L, Mcconnachie, A, Mccracken, H, Mellier, Y, Peng, C, Raichoor, A, Taylor, M, Tonry, J, Tully, R, Zhang, H, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: galaxies: clusters: individual (Virgo), 010504 meteorology & atmospheric sciences, Point source, Astrophysics, 01 natural sciences, law.invention, Telescope, Sky brightness, law, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Virgo Cluster, Galaxy, galaxies: distances and redshift, galaxies: photometry, Star cluster, Space and Planetary Science, Limiting magnitude, Globular cluster, galaxies: luminosity function, mass function, galaxies: star clusters: general
Abstract: International audience; The NGVS-IR project (Next Generation Virgo Cluster Survey-Infrared) is a contiguous, near-infrared imaging survey of the Virgo cluster of galaxies. It complements the optical wide-field survey of Virgo (NGVS). In its current state, NGVS-IR consists of K-s-band imaging of 4 deg(2) centered on M87 and J- and K-s-band imaging of similar to 16 deg(2) covering the region between M49 and M87. We present observations of the central 4 deg(2) centered on Virgo's core region. The data were acquired with WIRCam on the Canada-France-Hawaii Telescope, and the total integration time was 41 hr distributed over 34 contiguous tiles. A survey-specific strategy was designed to account for extended galaxies while still measuring accurate sky brightness within the survey area. The average 5s limiting magnitude is K-s = 24.4 AB mag, and the 50% completeness limit is K-s = 23.75 AB mag for point-source detections, when using only images with better than 0.” 7 seeing (median seeing 0.” 54). Star clusters are marginally resolved in these image stacks, and Virgo galaxies with mu(Ks) similar or equal to 24.4 AB mag arcsec(-2) are detected. Combining the K-s data with optical and ultraviolet data, we build the uiK(s) color-color diagram, which allows a very clean color-based selection of globular clusters in Virgo. This diagnostic plot will provide reliable globular cluster candidates for spectroscopic follow-up campaigns, needed to continue the exploration of Virgo's photometric and kinematic substructures, and will help the design of future searches for globular clusters in extragalactic systems. We show that the new uiK(s) diagram displays significantly clearer substructure in the distribution of stars, globular clusters, and galaxies than the gzK(s) diagram-the NGVS + NGVS-IR equivalent of the BzK diagram that is widely used in cosmological surveys. Equipped with this powerful new tool, future NGVS-IR investigations based on the uiK(s) diagram will address the mapping and analysis of extended structures and compact stellar systems in and around Virgo galaxies.
Published: 2014

38. The Next Generation Virgo Cluster Survey (NGVS). I. Introduction to the survey

Author: Chien Y. Peng, Hendrik Hildebrandt, Jj Kavelaars, John P. Blakeslee, Laura Ferrarese, Frédéric Bournaud, Billy Mahoney, Marc Huertas-Company, Eric W. Peng, Nicholas M. Ball, Eric Emsellem, J. Christopher Mihos, David Woods, Dean E. McLaughlin, Alan W. McConnachie, Nadine Manset, R. Brent Tully, Wim van Driel, Michael L. Balogh, Simona Mei, R. G. Carlberg, Chengze Liu, Luc Simard, Bernd Vollmer, Stéphane Courteau, Christine D. Wilson, Patrick Côté, Ludovic Van Waerbeke, Andrés Jordán, Marcin Sawicki, Jean-Charles Cuillandre, Lauren A. MacArthur, E. Ferriere, Giuseppe Gavazzi, Scott Chapman, Chantal Balkowski, Thomas Erben, Ariane Lançon, Raphael Gavazzi, D. Schade, Thomas H. Puzia, Martha Milkeraitis, Alessandro Boselli, Pierre-Alain Duc, Todd Burdullis, S. D. J. Gwyn, Yannick Mellier, Samuel Boissier, Patrick R. Durrell, Henk Hoekstra, James E. Taylor, P. Hudelot, Canada-France-Hawaii Telescope Corporation (CFHT), National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i [Honolulu] (UH), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Pontificia Universidad Católica de Chile (UC), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), University of Waterloo [Waterloo], Leiden Observatory [Leiden], Universiteit Leiden, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Canada (NRC), Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB), Department of Physics and Astronomy [Vancouver], University of British Columbia (UBC), Department of Astronomy and Astrophysics [Universty of Toronto], University of Toronto, Centre for Fusion Space and Astrophysics [Coventry] (CFSA), University of Warwick [Coventry], Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Max F. Perutz Laboratories, University Departments at the Vienna Biocenter, Institute of Microbiology and Genetics, Universität Wien, University of Exeter, ANR-10-BLAN-0506,VIRAGE,VIRAGE: Virgo - Alterations des Galaxies dans les Environnements denses(2010), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Universiteit Leiden [Leiden], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Universitá degli Studi di Milano-Bicocca, Universitá degli Studi di Milan-Bocca, PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Ferrarese, L, Côté, P, Cuillandre, J, Gwyn, S, Peng, E, Macarthur, L, Duc, P, Boselli, A, Mei, S, Erben, T, Mcconnachie, A, Durrell, P, Christopher Mihos, J, Jordán, A, Lançon, A, Puzia, T, Emsellem, E, Balogh, M, Blakeslee, J, van Waerbeke, L, Gavazzi, R, Vollmer, B, Kavelaars, J, Woods, D, Ball, N, Boissier, S, Courteau, S, Ferriere, E, Gavazzi, G, Hildebrandt, H, Hudelot, P, Huertas Company, M, Liu, C, Mclaughlin, D, Mellier, Y, Milkeraitis, M, Schade, D, Balkowski, C, Bournaud, F, Carlberg, R, Chapman, S, Hoekstra, H, Peng, C, Sawicki, M, Simard, L, Taylor, J, Brent Tully, R, van Driel, W, Wilson, C, Burdullis, T, Mahoney, B, and Manset, N
Subjects: Physics, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Cosmic distance ladder, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Virgo Cluster, Galaxy, Galactic halo, galaxies: clusters: individual: Virgo, galaxies: distances and redshifts, galaxies: general, galaxies: luminosity function, mass function, galaxies: photometry, galaxies: star clusters: general, Star cluster, Space and Planetary Science, Intracluster medium, 0103 physical sciences, Surface brightness, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Galaxy cluster, Astrophysics::Galaxy Astrophysics
Abstract: The Next Generation Virgo Cluster Survey (NGVS) is a program that uses the 1 deg2 MegaCam instrument on the Canada–France–Hawaii Telescope to carry out a comprehensive optical imaging survey of the Virgo cluster, from its core to its virial radius—covering a total area of 104 deg2—in the u*griz bandpasses. Thanks to a dedicated data acquisition strategy and processing pipeline, the NGVS reaches a point-source depth of g ≈ 25.9 mag (10σ) and a surface brightness limit of μ g ∼ 29 mag arcsec−2 (2σ above the mean sky level), thus superseding all previous optical studies of this benchmark galaxy cluster. In this paper, we give an overview of the technical aspects of the survey, such as areal coverage, field placement, choice of filters, limiting magnitudes, observing strategies, data processing and calibration pipelines, survey timeline, and data products. We also describe the primary scientific topics of the NGVS, which include: the galaxy luminosity and mass functions; the color–magnitude relation; galaxy scaling relations; compact stellar systems; galactic nuclei; the extragalactic distance scale; the large-scale environment of the cluster and its relationship to the Local Supercluster; diffuse light and the intracluster medium; galaxy interactions and evolutionary processes; and extragalactic star clusters. In addition, we describe a number of ancillary programs dealing with “foreground” and “background” science topics, including the study of high-inclination trans-Neptunian objects; the structure of the Galactic halo in the direction of the Virgo Overdensity and Sagittarius Stream; the measurement of cosmic shear, galaxy–galaxy, and cluster lensing; and the identification of distant galaxy clusters, and strong-lensing events.
Published: 2012

39. Black Hole Growth and Active Galactic Nuclei Obscuration by Instability-Driven Inflows in High-Redshift Disk Galaxies Fed by Cold Streams

Author: Frédéric Bournaud, Marcello Cacciato, Romain Teyssier, Avishai Dekel, Francesco Shankar, Stéphanie Juneau, Emanuele Daddi, Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Racah Institute of Physics, The Hebrew University of Jerusalem (HUJ), Racah Institute of Physics (Racah Institute of Physics), The Hebrew University of Jerusalem (HUJ)-Racah Institute of Physics, Steward observatory, University of Arizona, Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, European Project: 257720,EC:FP7:ERC,ERC-2010-StG_20091028,GALSICO(2011), University of Zurich, and Bournaud, F
Subjects: 530 Physics, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Astrophysics, Inflow, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Instability, Luminosity, Gravitation, 1912 Space and Planetary Science, Bulge, galaxies: high-redshift, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, galaxies: formation, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Redshift, Galaxy, Black hole, X-rays: galaxies, Space and Planetary Science, 10231 Institute for Computational Science, 3103 Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, galaxies: nuclei, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience; Disk galaxies at high redshift have been predicted to maintain high gas surface densities due to continuous feeding by intense cold streams leading to violent gravitational instability, transient features, and giant clumps. Gravitational torques between the perturbations drive angular momentum out and mass in, and the inflow provides the energy for keeping strong turbulence. We use analytic estimates of the inflow for a self-regulated unstable disk at a Toomre stability parameter Q ~ 1, and isolated galaxy simulations capable of resolving the nuclear inflow down to the central parsec. We predict an average inflow rate ~10 M ☉ yr-1 through the disk of a 1011 M ☉ galaxy, with conditions representative of z ~ 2 stream-fed disks. The inflow rate scales with disk mass and (1 + z)3/2. It includes clump migration and inflow of the smoother component, valid even if clumps disrupt. This inflow grows the bulge, while only a fraction of gsim 10-3 of it needs to accrete onto a central black hole (BH), in order to obey the observed BH-bulge relation. A galaxy of 1011 M ☉ at z ~ 2 is expected to host a BH of ~108 M ☉, accreting on average with moderate sub-Eddington luminosity L X ~ 1042-1043 erg s-1, accompanied by brighter episodes when dense clumps coalesce. We note that in rare massive galaxies at z ~ 6, the same process may feed ~109 M ☉ BH at the Eddington rate. High central gas column densities can severely obscure active galactic nuclei in high-redshift disks, possibly hindering their detection in deep X-ray surveys.
Published: 2011

40. Different star formation laws for disks versus starbursts at low and high redshifts

Author: Dominik A. Riechers, Fabian Walter, Helmut Dannerbauer, Emanuele Daddi, Chris Carilli, David Elbaz, F. Salmi, Pierluigi Monaco, Frédéric Bournaud, Mark Dickinson, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), National Optical Astronomy Observatory (NOAO), INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), UPGAL, ANR-07-BLAN-0228,DESIR,Deep galaxy Evolution Survey in the near Infra-Red(2007), ANR-08-JCJC-0008,UPGAL(2008), European Project: 240039,EC:FP7:ERC,ERC-2009-StG,UPGAL(2009), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), NOAO, Daddi, E., Elbaz, D., Walter, F., Bournaud, F., Salmi, F., Carilli, C., Dannerbauer, H., Dickinson, M., Monaco, Pierluigi, and Riechers, D.
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), formation [galaxies], observations -infrared, FOS: Physical sciences, galaxies: starburst, Astrophysics, Large range, Astrophysics::Cosmology and Extragalactic Astrophysics, Rotation, 01 natural sciences, galaxies [infrared], formation -cosmology, Luminosity, infrared: galaxies, galaxies -galaxies, 0103 physical sciences, galaxies, evolution, galaxies: formation, Astro-ph, 010303 astronomy & astrophysics, evolution [galaxies], Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, Star formation, starburst [galaxies], Astronomy and Astrophysics, Observable, Mass ratio, cosmology: observations, galaxies: evolution, Redshift, Galaxy, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], 13. Climate action, Space and Planetary Science, Law, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], starburst -galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, observation [cosmology]
Abstract: We present evidence that 'bona fide' disks and starburst systems occupy distinct regions in the gas mass versus star formation (SF) rate plane, both for the integrated quantities and for the respective surface densities. This result is based on CO observations of galaxy populations at low and high redshifts, and on the current consensus for the CO luminosity to gas mass conversion factors. The data suggest the existence of two different star formation regimes: a long-lasting mode for disks and a more rapid mode for starbursts, the latter probably occurring during major mergers or in dense nuclear SF regions. Both modes are observable over a large range of SF rates. The detection of CO emission from distant near-IR selected galaxies reveals such bimodal behavior for the first time, as they allow us to probe gas in disk galaxies with much higher SF rates than are seen locally. The different regimes can potentially be interpreted as the effect of a top-heavy IMF in starbursts. However, we favor a different physical origin related to the fraction of molecular gas in dense clouds. The IR luminosity to gas mass ratio (i.e., the SF efficiency) appears to be inversely proportional to the dynamical (rotation) timescale. Only when accounting for the dynamical timescale, a universal SF law is obtained, suggesting a direct link between global galaxy properties and the local SF rate., 5 pages, 4 figures. ApJ Letters in press
Published: 2010

41. Stellar kinematics for the central spheroid in the Polar Disk Galaxy NGC4650A

Author: J. S. Gallagher, Roberto P. Saglia, Francoise Combes, M. Capaccioli, Kenneth C. Freeman, M. Arnaboldi, Ortwin Gerhard, F. Bournaud, Enrica Iodice, Linda S. Sparke, INAF-Osservatorio Astronomico di Capodimonte (INAF-OAC), INAF-Osservatorio Astrofisico di Torino (INAF-OATo), Max-Planck-Institut für Extraterrestriche Physik (MPE), University of Wisconsin-Madison, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), University of Naples Federico II = Università degli studi di Napoli Federico II, Mount Stromlo Observatory, Australian National University, Henry, Florence, Iodice, E, Arnaboldi, M, Saglia, R. P., Sparke, L. S., Gerhard, O, Gallagher, J. S., Combes, F, Bournaud, F, Capaccioli, Massimo, and Freeman, K. C.
Subjects: Physics, Stellar kinematics, Astrophysics (astro-ph), Spheroid, Velocity dispersion, FOS: Physical sciences, Astronomy and Astrophysics, Kinematics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Spectral line, Galaxy, Accretion (astrophysics), Space and Planetary Science, Polar, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract: We have obtained high angular resolution, high signal-to-noise spectra of the Calcium triplet absorption lines on the photometric axes of the stellar spheroid in the polar disk galaxy NGC4650A. Along the major axis, the observed rotation and velocity dispersion measurements show the presence of a kinematically decoupled nucleus, and a flat velocity dispersion profile. The minor axis kinematics is determined for the first time: along this direction some rotation is measured, and the velocity dispersion is nearly constant and slightly increases at larger distances from the center. The new high resolution kinematic data suggest that the stellar component in NGC4650A resembles a nearly-exponential oblate spheroid supported by rotation. The main implications of these results on the previous mass models for NGC4650A are discussed. Moreover, the new kinematic data set constraints on current models for the formation scenarios of Polar Ring Galaxies (PRGs), supporting a slow accretion rather then a secondary strong dissipative event., Comment: 25 pages, 8 figures, accepted for publication in the Astrophysical Journal
Published: 2006
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42. Polar Ring Galaxies and the Tully Fisher relation: implications for the dark halo shape

Author: Enrica Iodice, Linda S. Sparke, Wim van Driel, Francoise Combes, F. Bournaud, Massimo Capaccioli, Magda Arnaboldi, Arnaboldi, M., Iodice, E., Bournaud, F., Combes, F., Sparke, L. S., van Driel, W., Capaccioli, Massimo, INAF-Osservatorio Astronomico di Capodimonte (INAF-OAC), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), University of Wisconsin-Madison, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Spiral galaxy, Astrophysics (astro-ph), Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Tully–Fisher relation, Ring (chemistry), Disc galaxy, Galaxy, Luminosity, Galactic halo, Dark matter halo, Space and Planetary Science, Elliptical galaxy, Polar, Halo, Disc, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Line (formation)
Abstract: We have investigated the Tully-Fisher relation for Polar Ring Galaxies (PRGs), based on near infrared, optical and HI data available for a sample of these peculiar objects. The total K-band luminosity, which mainly comes from the central host galaxy, and the measured HI linewidth at 20% of the peak line flux density, which traces the potential in the polar plane, place most polar rings of the sample far from the Tully-Fisher relation defined for spiral galaxies, with many PRGs showing larger HI linewidths than expected for the observed K band luminosity. This result is confirmed by a larger sample of objects, based on B-band data. This observational evidence may be related to the dark halo shape and orientation in these systems, which we study by numerical modeling of PRG formation and dynamics: the larger rotation velocities observed in PRGs can be explained by a flattened polar halo, aligned with the polar ring., 22 pages, 8 postscript figures, accepted for publication in Astrophysical Journal
Published: 2002

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