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We present new JWST NIRSpec integral field spectroscopy (IFS) data for the luminous infrared galaxy NGC 7469, a nearby (70.6 Mpc) active galaxy with a Seyfert 1.5 nucleus that drives a highly ionized gas outflow and a prominent nuclear star-forming ring. Using the superb sensitivity and high spatial resolution of the JWST instrument NIRSpec IFS, we investigate the role of the Seyfert nucleus in the excitation and dynamics of the circumnuclear gas. Our analysis focuses on the [Fe ii ], H2, and hydrogen recombination lines that trace the radiation/shocked-excited molecular and ionized interstellar medium around the active galactic nucleus (AGN). We investigate gas excitation through H2/Br γ and [Fe ii ]/Pa β emission line ratios and find that photoionization by the AGN dominates within the central 300 pc of the galaxy except in a small region that shows signatures of shock-heated gas; these shock-heated regions are likely associated with a compact radio jet. In addition, the velocity field and velocity dispersion maps reveal complex gas kinematics. Rotation is the dominant feature, but we also identify noncircular motions consistent with gas inflows as traced by the velocity residuals and the spiral pattern in the Pa α velocity dispersion map. The inflow is 2 orders of magnitude higher than the AGN accretion rate. The compact nuclear radio jet has enough power to drive the highly ionized outflow. This scenario suggests that the inflow and outflow are in a self-regulating feeding–feedback process, with a contribution from the radio jet helping to drive the outflow. [ABSTRACT FROM AUTHOR]

Near the center of the Puppis A supernova remnant a series of nested, optically emitting rings of high-velocity ejecta (known as "the Swirl") were identified several decades ago by Winkler et al. To date, no follow-up observations of these rings have been published, and their physical origin has remained a mystery. We present results of integral field spectroscopy of the Swirl using the Wide Field Integral Spectrograph on the 2.3 m telescope at Siding Spring Observatory in Australia. The outermost ring exhibits a nitrogen-rich spectrum blueshifted to 1350 km s−1, with smaller blueshifted rings within the first exhibiting mostly oxygen-rich spectra moving at 1000 and 750 km s−1. The structures are connected by material of intermediate velocity and variable composition, including sulfur-rich material. The Swirl is turbulent and shock-excited, and contains as much as 0.5 M ⊙ of metal-rich material. The chemical composition and exclusively blueshifted radial velocities of the Swirl are consistent with progressively deeper nucleosynthetic layers in a massive progenitor star. We suggest the possibility that the Swirl marks a "funnel" carved into the supernova ejecta by a close, massive binary companion at the moment of explosion. [ABSTRACT FROM AUTHOR]

The host galaxies of tidal disruption events (TDEs) have been shown to possess peculiar properties, including high central light concentrations, unusual star formation histories, and "green" colors. The ubiquity of these large-scale galaxy characteristics among TDE host populations suggests that they may serve to boost the TDE rate in such galaxies by influencing the nuclear stellar dynamics. We present the first population study of integral field spectroscopy for 13 TDE host galaxies across all spectral classes and X-ray brightnesses with the purpose of investigating their large-scale properties. We derive the black hole masses via stellar kinematics (i.e., the M – σ relation) and find masses in the range 5.0 ≲ log (M BH / M ⊙) ≲ 8.0 , with a distribution dominated by black holes with M BH ∼ 106 M ⊙. We find one object with M BH ≳ 108 M ⊙, above the "Hills mass", which if the disrupted star was of solar type, allows a lower limit of a ≳ 0.16 to be placed on its spin, lending further support to the proposed connection between featureless TDEs and jetted TDEs. We also explore the level of rotational support in the TDE hosts, quantified by (V / σ) e , a parameter that has been shown to correlate with the stellar age and may explain the peculiar host-galaxy preferences of TDEs. We find that the TDE hosts exhibit a broad range in (V / σ) e following a similar distribution as E + A galaxies, which have been shown to be overrepresented among TDE host populations. [ABSTRACT FROM AUTHOR]

We develop a novel approach to measure the dust attenuation properties of galaxies, including the dust opacity, the shape of the attenuation curve, and the strength of the 2175 Å absorption feature. From an observed spectrum, the method uses a model-independent approach to derive a relative attenuation curve with an absolute amplitude calibrated using NIR photometry. The dust-corrected spectrum is fitted with stellar population models to derive the dust-free model spectrum, which is compared with the observed SED/spectrum from NUV to NIR to determine the dust attenuation properties. We apply this method to investigate dust attenuation on kiloparsec scales using a sample of 134 galaxies with integral field spectroscopy from MaNGA, NIR imaging from 2MASS, and NUV imaging from Swift/UVOT. We find that the attenuation curve slope and the 2175 Å bump in both the optical and NUV span a wide range at kiloparsec scales. The slope is shallower at higher optical opacity, regardless of the specific star formation rate (sSFR), the minor-to-major axis ratio (b / a) of the galaxies, and the location of spaxels within individual galaxies. The 2175 Å bump presents a strong negative correlation with the sSFR, while the correlations with the optical opacity, b / a, and the locations within individual galaxies are all weak. All of these trends appear to be independent of the stellar mass of the galaxies. Our results support the scenario that the variation of the 2175 Å bump is driven predominantly by processes related to star formation, such as the destruction of small dust grains by UV radiation in star-forming regions. [ABSTRACT FROM AUTHOR]

Deep Very Large Telescope/MUSE optical integral field spectroscopy has recently revealed an abundant population of ultra-faint galaxies (M UV ≈ −15; 0.01 L ⋆) at z = 2.9−6.7 due to their strong Ly α emission with no detectable continuum. The implied Ly α equivalent widths can be in excess of 100–200 Å, challenging existing models of normal star formation and indicating extremely young ages, small stellar masses, and a very low amount of metal enrichment. We use JWST/NIRSpec's microshutter array to follow up 45 of these galaxies (11 hr in G235M/F170LP and 7 hr in G395M/F290LP), as well as 45 lower-equivalent width Ly α emitters. Our spectroscopy covers the range 1.7−5.1 micron in order to target strong optical emission lines: H α, [O iii ], H β, and [N II]. Individual measurements as well as stacks reveal line ratios consistent with a metal-poor nature (2%−40% Z ⊙, depending on the calibration). The galaxies with the highest equivalent widths of Ly α, in excess of 90 Å, have lower [N II]/H α (1.9 σ) and [O iii ]/H β (2.2 σ) ratios than those with lower equivalent widths, implying lower gas-phase metallicities at a combined significance of 2.4 σ. This implies a selection based on Ly α equivalent width is an efficient technique for identifying younger, less chemically enriched systems. [ABSTRACT FROM AUTHOR]

We analyze the cool gas in and around 14 nearby galaxies (at z < 0.1) mapped with the Sloan Digital Sky Survey IV MaNGA survey by measuring absorption lines produced by gas in spectra of background quasars/active galactic nuclei at impact parameters of 0–25 effective radii from the galactic centers. Using Hubble Space Telescope/Cosmic Origins Spectrograph, we detect absorption at the galactic redshift and measure or constrain column densities of neutral (H i, N i, O i, and Ar i), low-ionization (Si ii, S ii, C ii, N ii, and Fe ii), and high-ionization (Si iii, Fe iii, N v, and O vi) species for 11 galaxies. We derive the ionization parameter and ionization-corrected metallicity using cloudy photoionization models. The H i column density ranges from ∼1013 to ∼1020 cm−2 and decreases with impact parameter for r ≳ R e . Galaxies with higher stellar mass have weaker H i absorption. Comparing absorption velocities with MaNGA radial velocity maps of ionized gas line emissions in galactic disks, we find that the neutral gas seen in absorption corotates with the disk out to ∼10 R e . Sight lines with lower elevation angles show lower metallicities, consistent with the metallicity gradient in the disk derived from MaNGA maps. Higher-elevation angle sight lines show higher ionization, lower H i column density, supersolar metallicity, and velocities consistent with the direction of galactic outflow. Our data offer the first detailed comparisons of circumgalactic medium (CGM) properties (kinematics and metallicity) with extrapolations of detailed galaxy maps from integral field spectroscopy; similar studies for larger samples are needed to more fully understand how galaxies interact with their CGM. [ABSTRACT FROM AUTHOR]

Despite the importance of feedback from active galactic nuclei (AGNs) in models of galaxy evolution, observational constraints on the influence of AGN feedback on star formation remain weak. To this end, we have compared the star formation trends of 279 low-redshift AGN galaxies with 558 inactive control galaxies using integral field unit spectroscopy from the Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory survey. With a Gaussian-process-based methodology, we reconstruct nonparametric star formation histories in spatially resolved spaxels covering the face of each galaxy. Based on the galaxy-wide star formation rates (SFRs) alone, we find no obvious signatures of AGN feedback. However, the AGN galaxies have significantly suppressed central (kiloparsec-scale) SFRs, lying up to a factor of 2 below those of the control galaxies, providing direct observational evidence of AGN feedback suppressing star formation. The suppression of central SFRs in the AGN galaxies began in the central regions ∼6 Gyr ago (redshift z ∼ 0.7), taking place over a few gigayears. A small subset of the AGN galaxies were rapidly driven to quiescence shortly before being observed (in the last 500 Myr), potentially indicating instances of AGN-driven feedback. More frequently, however, star formation continues in the AGN galaxies, with suppression primarily in the central regions. This is suggestive of a picture in which integrated (gigayear-timescale) AGN feedback can significantly affect central star formation, but may be inefficient in driving galaxy-wide quenching in low-redshift galaxies, instead leaving them in the green valley. [ABSTRACT FROM AUTHOR]

Dwarf galaxies located in extremely underdense cosmic voids are excellent test beds for disentangling the effects of large-scale environments on galaxy formation and evolution. We present the first results of the Dwarfs in Void Environments Survey, which has obtained integral field spectroscopy for low-mass galaxies (M ⋆ = 107–109 M ⊙) located inside (N = 21) and outside (N = 9) cosmic voids using the Keck Cosmic Web Imager. Using measurements of stellar line-of-sight rotational velocity v rot and velocity dispersion σ ⋆, we test the tidal stirring hypothesis, which posits that dwarf spheroidal galaxies are formed through tidal interactions with more massive host galaxies. We measure low values of v rot/ σ ⋆ ≲ 2 for our sample of isolated dwarf galaxies, and we find no trend between v rot/ σ ⋆ and the distance from a massive galaxy d L ⋆ out to d L ⋆ ∼ 10 Mpc. These suggest that dwarf galaxies can become dispersion-supported, "puffy" systems even in the absence of environmental effects like tidal interactions. We also find indications of an upward trend between v rot/ σ ⋆ and galaxy stellar mass, perhaps implying that stellar disk formation depends on mass rather than environment. Although some of our conclusions may be slightly modified by systematic effects, our main result still holds: that isolated low-mass galaxies may form and remain as puffy systems rather than the dynamically cold disks predicted by classical galaxy formation theory. [ABSTRACT FROM AUTHOR]

We present the stellar radial velocity analysis of the central 1 ′ Ă— 1 ′ of the young massive Small Magellanic Cloud star cluster NGC 346. Using VLT/MUSE integral field spectroscopy in combination with Hubble Space Telescope photometry, we extract 103 spectra of cluster member stars suited to measure accurate line-of-sight kinematics. The cluster member stars show two distinct velocity groups at v 1 = âˆ' 3.3 âˆ' 0.2 + 0.3 km s âˆ' 1 and v 2 = 2.6 âˆ' 0.1 + 0.1 km s âˆ' 1 , relative to the systemic velocity of (165.5 ± 0.2) km sâˆ'1, and hint at a third group at v 3 = 9.4 âˆ' 0.1 + 0.1 km s âˆ' 1 . We show that there is neither a correlation between the velocity groups and the spatial location of the stars, nor their locus on optical colorâ€"magnitude diagrams, which makes the stellar velocity a key parameter to separate individual stellar components in such a young star cluster. Velocity group 2 shows clear rotation with Ω2 =(âˆ'0.4 ± 0.1) Myrâˆ'1, corresponding to (âˆ'4.9 ± 0.7) km sâˆ'1 at radial distance of 10 pc from the center, a possible remnant of the formation process of NGC 346 through the hierarchical collapse of the giant molecular cloud. The ionizing gas has lost any natal kinematic imprint and shows clear expansion, driven by far-ultraviolet fluxes and stellar winds of the numerous OB stars in the cluster center. The size of this expanding bubble and its expansion velocity of 7.9 km sâˆ'1 are in excellent agreement with the estimate that the latest star formation episode occurred about two million years ago. [ABSTRACT FROM AUTHOR]

Pulsar H α bow shocks provide rare opportunities to constrain the energetics and kinematics of the relativistic pulsar wind. We have acquired optical imaging and integral field unit spectroscopy of the bow shock of the millisecond pulsar PSR J1959+2048, measuring the shock symmetry axis at a position angle = 213.2 ± 0.°2 and showing that this slow nonradiative shock has a broad-to-narrow line component ratio I b / I n = 4. The data show that the pulsar’s velocity lies 2.°2 out of the plane of the sky. Coupled with a new fit for its timing proper motion, giving ÎĽ tot = 30.05 mas yrâˆ'1 and a Very Long Baseline Array (VLBA) interferometric parallax measurement giving d = 2.57 âˆ' 0.77 + 1.84 kpc (90% range), we have unusually complete information on the pulsar kinematics. The bow shock constraints on the wind momentum flux imply that, at the best-fit parallax distance, the pulsar moment of inertia must be very large and/or the H α efficiency at its modest shock velocity must be very high. [ABSTRACT FROM AUTHOR]

The prospect of combining integral field spectroscopy with the solar gravitational lens (SGL) to spectrally and spatially resolve the surfaces and atmospheres of extrasolar planets is investigated. The properties of hyperbolic orbits visiting the focal region of the SGL are calculated analytically, demonstrating trade-offs between departure velocity and time of arrival, as well as gravity assist maneuvers and heliocentric angular velocity. Numerical integration of the solar barycentric motion demonstrates that navigational acceleration of dv ≲ 80 m s + 6.7 m s t year is needed to obtain and maintain alignment. Obtaining target ephemerides of sufficient precision is an open problem. The optical properties of an oblate gravitational lens are reviewed, including calculations of the magnification and the point-spread function that forms inside a telescope. Image formation for extended, incoherent sources is discussed when the projected image is smaller than, approximately equal to, and larger than the critical caustic. Sources of contamination that limit observational signal-to-noise ratio (S/N) are considered in detail, including the Sun, the solar corona, the host star, and potential background objects. A noise mitigation strategy of spectrally and spatially separating the light using integral field spectroscopy is emphasized. A pseudo-inverse-based image reconstruction scheme demonstrates that direct reconstruction of an Earth-like source from single measurements of the Einstein ring is possible when the critical caustic and observed S/N are sufficiently large. In this arrangement, a mission would not require multiple telescopes or navigational symmetry breaking, enabling continuous monitoring of the atmospheric composition and dynamics on other planets. [ABSTRACT FROM AUTHOR]

Integral field spectroscopy of high-redshift galaxies has become a powerful tool for understanding their dynamics and evolutionary states. However, in the case of gravitationally lensed systems, it has proved difficult to model both lensing and intrinsic kinematics in a way that takes full advantage of the information available in the spectral domain. In this paper, we introduce a new method for pixel-based source reconstruction that alters standard regularization schemes for two-dimensional (2D) data in a way that leverages kinematic information in a physically motivated but flexible fashion, and that is better suited to the three-dimensional (3D) nature of integral field data. To evaluate the performance of this method, we compare its results to those of a more traditional 2D nonparametric approach using mock Atacama Large Millimeter/submillimeter Array (ALMA) observations of a typical high-redshift dusty star-forming galaxy. We find that 3D regularization applied to an entire data cube reconstructs a source’s intensity and velocity structure more accurately than 2D regularization applied to separate velocity channels. Cubes reconstructed with 3D regularization also have more uniform noise and resolution properties and are less sensitive to the signal-to-noise ratio of individual velocity channels than the results of 2D regularization. Our new approach to modeling integral field observations of lensed systems can be implemented without making restrictive a priori assumptions about intrinsic kinematics, and opens the door to new observing strategies that prioritize spectral resolution over spatial resolution (e.g., for multiconfiguration arrays like ALMA). [ABSTRACT FROM AUTHOR]

Physical and chemical properties of the interstellar medium (ISM) at subgalactic (∼kiloparsec) scales play an indispensable role in controlling the ability of gas to form stars. In this paper, we use the TNG50 cosmological simulation to explore the physical parameter space of eight resolved ISM properties in star-forming regions to constrain the areas of this hyperspace where most star-forming environments exist. We deconstruct our simulated galaxies spanning a wide range of mass (M⋆ = 107–1011M⊙) and redshift (0 ≤ z ≤ 3) into kiloparsec-sized regions and statistically analyze the gas/stellar surface densities, gas metallicity, vertical stellar velocity dispersion, epicyclic frequency, and dark-matter volumetric density representative of each region in the context of their star formation activity and environment (radial galactocentric location). By examining the star formation rate (SFR) weighted distributions of these properties, we show that stars primarily form in two distinct environmental regimes, which are brought about by an underlying bicomponent radial SFR profile in galaxies. We examine how the relative prominence of these regimes depends on galaxy mass and cosmic time. We also compare our findings with those from integral field spectroscopy observations and find similarities as well as departures. Further, using dimensionality reduction, we characterize the aforementioned hyperspace to reveal a high degree of multicollinearity in relationships among ISM properties that drive the distribution of star formation at kiloparsec scales. Based on this, we show that a reduced 3D representation underpinned by a multivariate radius relationship is sufficient to capture most of the variance in the original 8D space. [ABSTRACT FROM AUTHOR]

Using integral field unit spectroscopy, we present here the spatially resolved morphologies of [S ii ] λ 6717,6731/H α and [S ii ] λ 6717,6731/[O iii ] λ 5007 emission line ratios for the first time in a blueberry Ly α emitter (BBLAE) at z ∼ 0.047. Our derived morphologies show that the extreme starburst region of the BBLAE, populated by young (≤10 Myr), massive Wolfâ€"Rayet stars, is [S ii ] deficient, while the rest of the galaxy is [S ii ] enhanced. We infer that the extreme starburst region is density-bounded (i.e., optically thin to ionizing photons), and the rest of the galaxy is ionization-bounded, indicating a Blister-type morphology. We find that the previously reported small escape fraction (10%) of Ly α photons is from our identified density-bounded H ii region of the BBLAE. This escape fraction is likely constrained by a porous dust distribution. We further report a moderate correlation between [S ii ] deficiency and inferred Lyman continuum (LyC) escape fraction using a sample of confirmed LyC leakers studied in the literature, including the BBLAE studied here. The observed correlation also reveals its dependency on the stellar mass and gas-phase metallicity of the leaky galaxies. Finally, the future scope and implications of our work are discussed in detail. [ABSTRACT FROM AUTHOR]

Using integral field unit spectroscopy, we present here the spatially resolved morphologies of [S ii ]λ6717,6731/Hα and [S ii ]λ6717,6731/[O iii ]λ5007 emission line ratios for the first time in a blueberry Lyα emitter (BBLAE) at z ∼ 0.047. Our derived morphologies show that the extreme starburst region of the BBLAE, populated by young (≤10 Myr), massive Wolf–Rayet stars, is [S ii ] deficient, while the rest of the galaxy is [S ii ] enhanced. We infer that the extreme starburst region is density-bounded (i.e., optically thin to ionizing photons), and the rest of the galaxy is ionization-bounded, indicating a Blister-type morphology. We find that the previously reported small escape fraction (10%) of Lyα photons is from our identified density-bounded H ii region of the BBLAE. This escape fraction is likely constrained by a porous dust distribution. We further report a moderate correlation between [S ii ] deficiency and inferred Lyman continuum (LyC) escape fraction using a sample of confirmed LyC leakers studied in the literature, including the BBLAE studied here. The observed correlation also reveals its dependency on the stellar mass and gas-phase metallicity of the leaky galaxies. Finally, the future scope and implications of our work are discussed in detail. [ABSTRACT FROM AUTHOR]

In this work, we propose a proper plasma analysis practice (PPAP), an updated procedure of plasma diagnostics in the era of spatially resolved spectroscopy. In particular, we emphasize the importance of performing both of the extinction correction and the direct method of plasma diagnostics simultaneously as an integrated process. This approach is motivated by the reciprocal dependence between critical parameters in these analyses, which can be resolved by iteratively seeking a converged solution. The use of PPAP allows us to eliminate unnecessary assumptions that prevent us from obtaining an exact solution at each element of the spectral imaging data. Using a suite of Hubble Space Telescope/WFC3 narrowband images of the planetary nebula, NGC 6720, we validate PPAP by (1) simultaneously and self-consistently deriving the extinction, c(Hβ), and electron density/temperature distribution, (ne([S ii ]), Te([N ii ])), maps that are consistent with each other, and (2) obtaining identical metal abundance distribution maps, (n(N+)/n(H+), n(S+)/n(H+)), from multiple emission line maps at different wavelengths/transition energies. We also determine that the derived c(Hβ) consists both of the interstellar medium and circumsource components and that the ionized gas-to-dust mass ratio in the main ring is at least 437 and as high as about 1600. We find that, unless we deliberately seek self-consistency, uncertainties at tens of % can easily arise in outcomes, making it impossible to discern actual spatial variations that occurs at the same level, defeating the purpose of conducting spatially resolved spectroscopic observations. [ABSTRACT FROM AUTHOR]

We investigate the dust attenuation in both stellar populations and ionized gas in kiloparsec-scale regions in nearby galaxies using integral field spectroscopy data from MaNGA MPL-9. We identify star-forming (H ii) and diffuse ionized gas (DIG) regions from MaNGA data cubes. From the stacked spectrum of each region, we measure the stellar attenuation, , using the technique developed by Li et al., as well as the gas attenuation, , from the Balmer decrement. We then examine the correlation of , , , and with 16 regional/global properties, and for regions with different Hα surface brightnesses (ΣHα). We find a stronger correlation between and in regions of higher ΣHα. The luminosity-weighted age (tL) is found to be the property that is the most strongly correlated with , and consequently, with and. At fixed ΣHα, tL is linearly and negatively correlated with at all ages. Gas-phase metallicity and ionization level are important for the attenuation in the gas. Our results indicate that the ionizing source for DIG regions is likely distributed in the outskirts of galaxies, while for H ii regions, our results can be well explained by the two-component dust model of Charlot & Fall. [ABSTRACT FROM AUTHOR]

The mass of a supermassive black hole (MBH) is a fundamental property that can be obtained through observational methods. Constraining MBH through multiple methods for an individual galaxy is important for verifying the accuracy of different techniques and for investigating the assumptions inherent in each method. However, there exist only a few galaxies where multiple MBH measurement techniques can be applied. NGC 4151 is one of these rare galaxies for which multiple methods can be used: stellar and gas dynamical modeling because of its proximity (D = 15.8 ± 0.4 Mpc from Cepheids), and reverberation mapping because of its active accretion. In this work, we reanalyzed H-band integral field spectroscopy of the nucleus of NGC 4151 from Gemini NIFS, improving the analysis at several key steps. We then constructed a wide range of axisymmetric dynamical models with the new orbit-superposition code F orstand. One of our primary goals is to quantify the systematic uncertainties in MBH arising from different combinations of the deprojected density profile, inclination, intrinsic flattening, and mass-to-light ratio. As a consequence of uncertainties on the stellar luminosity profile arising from the presence of the active galactic nucleus, our constraints on MBH are rather weak. Models with a steep central cusp are consistent with no black hole; however, in models with more moderate cusps, the black hole mass lies within the range of 0.25 × 107M⊙ ≲ MBH ≲ 3 × 107M⊙. This measurement is somewhat smaller than the earlier analysis presented by Onken et al. but agrees with previous MBH values from gas dynamical modeling and reverberation mapping. Future dynamical modeling of reverberation data, as well as IFU observations with JWST, will aid in further constraining the mass of the central supermassive black hole in NGC 4151. [ABSTRACT FROM AUTHOR]

We investigate the star formation histories (SFHs) of massive red spiral galaxies with stellar mass M* > 1010.5M⊙, and make comparisons with blue spirals and red ellipticals of similar masses. We make use of the integral field spectroscopy from the Sloan Digital Sky Survey IV/DR15 MaNGA sample, and estimate spatially resolved SFHs and stellar population properties of each galaxy by applying a Bayesian spectral fitting code to the MaNGA spectra. We find that both red spirals and red ellipticals have experienced only one major star formation episode at early times, and the result is independent of the adopted SFH model. On average, more than half of their stellar masses were formed >10 Gyr ago, and more than 90% were formed >6 Gyr ago. The two types of galaxies show similarly flat profiles in a variety of stellar population parameters: old stellar ages indicated by D4000 (the spectral break at around 4000 Å), high stellar metallicities, large Mgb/Fe ratios indicating fast formation, and little stellar dust attenuation. In contrast, although blue spirals also formed their central regions >10 Gyr ago, both their central regions and outer disks continuously form stars over a long timescale. Our results imply that massive red spirals are likely to share some common processes of formation (and possibly quenching) with massive red ellipticals in the sense that both types were formed at z > 2 through a fast formation process. Possible mechanisms for the formation and quenching of massive red spirals are discussed. [ABSTRACT FROM AUTHOR]

We report the direct abundances for the galaxy NGC 2403 as observed by the CHemical Abundances Of Spirals (CHAOS) project. Using the Multi-Object Double Spectrograph on the Large Binocular Telescope, we observe two fields with H ii regions that cover an Rg/Re range of 0.18–2.31. Thirty-two H ii regions contain at least one auroral line detection, and we detect a total of 122 temperature-sensitive auroral lines. Here, for the first time, we use the intrinsic scatter in the Te–Te diagrams, added in quadrature to the uncertainty on the measured temperature, to determine the uncertainty on an electron temperature inferred for one ionization zone from a measurement in a different ionization zone. We then use all available temperature data within a H ii region to obtain a weighted-average temperature within each ionization zone. We rederive the oxygen abundances of all CHAOS galaxies using this new temperature prioritization method, and we find that the gradients are consistent with the results of a recent study of Berg et al. For NGC 2403, we measure a direct oxygen abundance gradient of −0.09(±0.03) dex/Re, with an intrinsic dispersion of 0.037(±0.017) dex and a N/O abundance gradient of −0.17(±0.03) dex/Re with an intrinsic dispersion of 0.060(±0.018) dex. For direct comparison, we use the line intensities from an earlier study of NGC 2403 by Berg et al. and find their recomputed values for the O/H and N/O gradients are consistent with ours. [ABSTRACT FROM AUTHOR]

Ultraluminous infrared galaxies (ULIRGs) represent a critical stage in the merger-driven evolution of galaxies when active galactic nucleus (AGN) activity is common and AGN feedback is expected. We present high-sensitivity and large field-of-view integral field spectroscopy of the ULIRG Mrk 273 using new data from the Keck Cosmic Web Imager (KWCI). The KCWI data capture the complex nuclear region and the two extended nebulae in the northeast (NE) and southwest (SW) to ∼20 kpc scales. Kinematics in the nuclear region show a fast, extended, bipolar outflow in the direction of the previously reported nuclear superbubbles spanning ∼5 kpc, two to three times greater than the previously reported size. The larger-scale extended nebulae on ∼20 kpc show fairly uniform kinematics with FWHM ∼ 300 km s−1 in the SW nebula and FWHM ∼ 120 km s−1 in the NE nebula. We detect for the first time high-ionization [Ne v ] 3426, [O iii ] 4363, and He ii 4684 emission lines in the extended NE nebula. Emission line ratios in the nuclear region correlate with the kinematic structures, with the bipolar outflow and the less collimated "outflow regions" showing distinct line ratio trends. Line ratio diagnostics of high-ionization emission lines reveal a nontrivial contribution from shock plus precursor ionization in the NE nebula and the nuclear region mixed with AGN photoionization. These data are highly constraining for models of cool ionized gas existing 20 kpc from a galactic nucleus. [ABSTRACT FROM AUTHOR]

To determine the importance of merging galaxies to galaxy evolution, it is necessary to design classification tools that can identify the different types and stages of merging galaxies. Previously, using GADGET-3/SUNRISE simulations of merging galaxies and linear discriminant analysis (LDA), we created an accurate merging galaxy classifier based on imaging predictors. Here, we develop a complementary tool, based on stellar kinematic predictors, derived from the same simulation suite. We design mock stellar velocity and velocity dispersion maps to mimic the specifications of the Mapping Nearby Galaxies at Apache Point (MaNGA) integral field spectroscopy (IFS) survey, and utilize an LDA to create a classification, based on a linear combination of 11 kinematic predictors. The classification varies significantly with mass ratio; the major (minor) merger classifications have a mean statistical accuracy of 80% (70%), a precision of 90% (85%), and a recall of 75% (60%). The major mergers are best identified by predictors that trace global kinematic features, while the minor mergers rely on local features that trace a secondary stellar component. While the kinematic classification is less accurate than the imaging classification, the kinematic predictors are better at identifying post-coalescence mergers. A combined imaging + kinematic classification has the potential to reveal more complete merger samples from imaging and IFS surveys such as MaNGA. We note that since the suite of simulations used to train the classifier covers a limited range of galaxy properties (i.e., the galaxies are of intermediate mass, and disk-dominated), the results may not be applicable to all MaNGA galaxies. [ABSTRACT FROM AUTHOR]

In the first paper of this series, we demonstrated that neural networks can robustly and efficiently estimate kinematic parameters for optical emission-line spectra taken by SITELLE at the Canada–France–Hawaii Telescope. This paper expands upon this notion by developing an artificial neural network to estimate the line ratios of strong emission lines present in the SN1, SN2, and SN3 filters of SITELLE. We construct a set of 50,000 synthetic spectra using line ratios taken from the Mexican Million Model database replicating H ii regions. Residual analysis of the network on the test set reveals the network's ability to apply tight constraints to the line ratios. We verified the network's efficacy by constructing an activation map, checking the [ N ii ] doublet fixed ratio, and applying a standard k-fold cross-correlation. Additionally, we apply the network to SITELLE observations of M33; the residuals between the algorithm's estimates and values calculated using standard fitting methods show general agreement. Moreover, the neural network reduces the computational costs by two orders of magnitude. Although standard fitting routines do consistently well depending on the signal-to-noise ratio of the spectral features, the neural network can also excels at predictions in the low signal-to-noise regime within the controlled environment of the training set as well as on observed data when the source spectral properties are well constrained by models. These results reinforce the power of machine learning in spectral analysis. [ABSTRACT FROM AUTHOR]

We investigate the stellar populations of passive spiral galaxies as a function of mass and environment, using integral field spectroscopy data from the Sydney-AAO Multi-object Integral field spectrograph Galaxy Survey. Our sample consists of 52 cluster passive spirals and 18 group/field passive spirals, as well as a set of S0s used as a control sample. The age and [Z/H] estimated by measuring Lick absorption line strength indices both at the center and within 1Re do not show a significant difference between the cluster and the field/group passive spirals. However, the field/group passive spirals with log(M⋆/M⊙) ≳ 10.5 show decreasing [α/Fe] along with stellar mass, which is ∼0.1 dex smaller than that of the cluster passive spirals. We also compare the stellar populations of passive spirals with S0s. In the clusters, we find that passive spirals show slightly younger age and lower [α/Fe] than the S0s over the whole mass range. In the field/group, stellar populations show a similar trend between passive spirals and S0s. In particular, [α/Fe] of the field/group S0s tend to be flattening with increasing mass above log(M⋆/M⊙) ≳ 10.5, similar to the field/group passive spirals. We relate the age and [α/Fe] of passive spirals to their mean infall time in phase space; we find a positive correlation, in agreement with the prediction of numerical simulations. We discuss the environmental processes that can explain the observed trends. The results lead us to conclude that the formation of the passive spirals and their transformation into S0s may significantly depend on their environments. [ABSTRACT FROM AUTHOR]

Feedback likely plays a vital role in the formation of dwarf galaxies. While stellar processes have long been considered the main source of feedback, recent studies have revealed tantalizing signs of active galactic nucleus (AGN) feedback in dwarf galaxies. In this paper, we report the results from an integral field spectroscopic study of a sample of eight dwarf galaxies with known AGNs and suspected outflows. Outflows are detected in seven of them. The outflows are fast, with 50th-percentile (median) velocity of up to ∼240 km s−1 and 80th-percentile line width reaching ∼1200 km s−1, in clear contrast with the more quiescent kinematics of the host gas and stellar components. The outflows are generally spatially extended on a scale of several hundred parsecs to a few kiloparsecs, although our data do not clearly resolve the outflows in three targets. The outflows appear to be primarily photoionized by the AGN rather than shocks or young, massive stars. The kinematics and energetics of these outflows suggest that they are primarily driven by the AGN, although the star formation activity in these objects may also contribute to the energy input. A small but nonnegligible portion of the outflowing material likely escapes the main body of the host galaxy and contributes to the enrichment of the circumgalactic medium. Overall, the impact of these outflows on their host galaxies is similar to those taking place in the more luminous AGNs in the low-redshift universe. [ABSTRACT FROM AUTHOR]

We present the first results from our "CGM at Cosmic Noon with KCWI" program to study gas flows in the circumgalactic medium (CGM) at z = 2–3. Combining the power of a high-resolution VLT/UVES quasar spectrum, a Hubble Space Telescope/Advanced Camera for Surveys image, and integral field spectroscopy with Keck/KCWI (Keck Cosmic Web Imager), we detected Lyα emission from a 1.7L* galaxy at zgal = 2.0711 associated with a Lyman limit system with weak Mg ii (Wr(2796) = 0.24 Å) in quasar field J143040+014939. The galaxy is star-forming (SFRFUV = 37.8 M⊙ yr−1) and clumpy: either an edge-on disk (i = 85°) or, less likely, a major merger. The background quasar probes the galaxy at an impact parameter of D = 66 kpc along the projected galaxy minor axis (Φ = 89°). From photoionization modeling of the absorption system, we infer a total line-of-sight CGM metallicity of. The absorption system is roughly kinematically symmetric about zgal, with a full Mg ii velocity spread of ∼210 km s−1. Given the galaxy–quasar orientation, CGM metallicity, and gas kinematics, we interpret this gas as an outflow that has likely swept up additional material. By modeling the absorption as a polar outflow cone, we find the gas is decelerating with average radial velocity Vout = 109–588 km s−1 for half-opening angles of θ0 = 14°–75°. Assuming a constant Vout, it would take on average tout ∼ 111–597 Myr for the gas to reach 66 kpc. The outflow is energetic, with a mass outflow rate of M⊙ yr−1 and mass loading factor of η < 1.4 ± 1.0. We aim to build a sample of ∼50 Mg ii absorber–galaxy pairs at this epoch to better understand gas flows when they are most actively building galaxies. [ABSTRACT FROM AUTHOR]

The search for new global scaling relations linking the physical properties of galaxies has a fundamental interest. Furthermore, their recovery from spatially resolved relations has been in the spotlight of integral field spectroscopy (IFS). In this study, we investigate the existence of global and local relations between stellar age (Age⋆) and gas-phase metallicity (Zg). To this aim, we analyze IFS data for a sample of 736 star-forming disk galaxies from the MaNGA survey. We report a positive correlation between the global Zg and D(4000) (an indicator of stellar age), with a slope that decreases with increasing galaxy mass. Locally, a similar trend is found when analyzing the Zg and D(4000) of the star-forming regions, as well as the residuals resulting from removing the radial gradients of both parameters. The local laws have systematically smaller slopes than the global one. We ascribe this difference to random errors that cause the true slope of the Age⋆–Zg relation to be systematically underestimated when performing a least-squares fitting. The explored relation is intimately linked with the already known relation between gas metallicity and star formation rate at fixed mass, both presenting a common physical origin. [ABSTRACT FROM AUTHOR]

Accurate active galactic nucleus (AGN) identifications and spatially resolved host galaxy properties are a powerful combination for studies of the role of AGNs and AGN feedback in the coevolution of galaxies and their central supermassive black holes. Here, we present robust identifications of 406 AGNs in the first 6261 galaxies observed by the integral field spectroscopy survey Mapping Nearby Galaxies at Apache Point Observatory. Instead of using optical line flux ratios, which can be difficult to interpret in light of the effects of shocks and metallicity, we identify the AGNs via mid-infrared Wide-field Infrared Survey Explorer colors, Swift/BAT ultrahard X-ray detections, NVSS and FIRST radio observations, and broad emission lines in SDSS spectra. We subdivide the AGNs into radio-quiet and radio-mode AGNs, and examine the correlations of the AGN classes with host galaxy star formation rates and stellar populations. When compared to the radio-quiet AGN host galaxies, we find that the radio-mode AGN host galaxies are preferentially elliptical, lie further beneath the star-forming main sequence (with lower star formation rates at fixed galaxy mass), have older stellar populations, and have more negative stellar age gradients with galactocentric distance (indicating inside-out quenching of star formation). These results establish a connection between radio-mode AGNs and the suppression of star formation. [ABSTRACT FROM AUTHOR]

SITELLE is a novel integral field unit spectroscopy instrument that has an impressive spatial (11 by 11 arcmin), spectral coverage, and spectral resolution (R ∼ 1–20,000). SIGNALS is anticipated to obtain deep observations (down to 3.6 × 10−17erg s−1 cm−2) of 40 galaxies, each needing complex and substantial time to extract spectral information. We present a method that uses Convolution Neural Networks (CNN) for estimating emission-line parameters in optical spectra obtained with SITELLE as part of the SIGNALS large program. Our algorithm is trained and tested on synthetic data representing typical emission spectra for H ii regions based on Mexican Million Models database (3MdB) BOND simulations. The network's activation map demonstrates its ability to extract the dynamical (broadening and velocity) parameters from a set of five emission lines (e.g., Hα, N [ ii ] doublet, and S [ ii ] doublet) in the SN3 (651–685 nm) filter of SITELLE. Once trained, the algorithm was tested on real SITELLE observations in the SIGNALS program of one of the southwest fields of M33. The CNN recovers the dynamical parameters with an accuracy better than 5 in regions with a signal-to-noise ratio greater than 15 over the Hα line. More importantly, our CNN method reduces calculation time by over an order of magnitude on the spectral cube with native spatial resolution when compared with standard fitting procedures. These results clearly illustrate the power of machine-learning algorithms for the use in future IFU-based missions. Subsequent work will explore the applicability of the methodology to other spectral parameters such as the flux of key emission lines. [ABSTRACT FROM AUTHOR]

We present Subaru/SCExAO+Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) broadband (JHK-band) integral field spectroscopy of HD 34700 A. CHARIS data recover HD 34700 A's disk ring and confirm multiple spirals discovered by Monnier et al. We set limits on substellar companions of ∼12 MJup at 0.″3 (in the ring gap) and ∼5 MJup at 0.″75 (outside the ring). The data reveal darkening effects on the ring and spiral, although we do not identify the origin of each feature such as shadows or physical features related to the outer spirals. Geometric albedos converted from the surface brightness suggest a greater scale height and/or prominently abundant submicron dust at position angles between ∼45° and 90°. Spiral fitting resulted in very large pitch angles (∼30°–50°); a stellar flyby of HD 34700 B or infall from a possible envelope is perhaps a reasonable scenario to explain the large pitch angles. [ABSTRACT FROM AUTHOR]

Gas interior to the bar of the Milky Way has recently been shown to be the closest example of a low-ionization (nuclear) emission region (LI(N)ER) in the universe. To better understand the nature of this gas, a sample of face-on galaxies with integral field spectroscopy is used to study the ionized gas conditions of 240 barred and 250 nonbarred galaxies, focusing on those that are most similar to the Milky Way. Strong optical line emission of [N ii ] λ6584, Hα, [O iii ] λ5007, and Hβ are used to diagnose the dominant ionization mechanisms of gas across galaxies and the Galaxy via Baldwin–Phillips–Terlevich diagrams. Barred galaxies show a strong suppression of star formation and an increase in composite and LI(N)ER-like spectra in their inner regions when compared with similar nonbarred counterparts. This effect is lessened in galaxies of very low () or very high () total stellar mass. Bar masks from Galaxy Zoo:3D show the bar's nonaxisymmetric effect on the ionized gas and help predict the face-on distribution of ionized gas conditions near the bar of the Milky Way. [ABSTRACT FROM AUTHOR]

The abundance of methyl formate (MF, HCOOCH3) in star-forming regions of the interstellar medium (ISM) suggests the presence of protonated MF (H+MF). However, no spectroscopic data exist for isolated H+MF. Here, we address the vibrational properties of H+MF and its H+MF-Ln≤2 clusters (L = Ar/N2) by infrared photodissociation (IRPD) spectroscopy and density functional theory calculations. Protonation of MF occurs at the CO oxygen, resulting in four different isomers arising from the syn/anti (s/a) and cis/trans (c/t) orientation between OCH3 and the excess proton. H+MF photofragments into protonated methanol by CO elimination. The IRPD spectrum exhibits redshifted OH stretch bands of the most stable H+MF(t/s) and H+MF(c/a) conformers because of the high internal energy required for dissociation. Tagging of H+MF with inert ligands drastically reduces both the internal energy and the dissociation threshold. The resulting higher-resolution IRPD spectra allow determination of the most stable H+MF rotamers as (t/s) and (c/a). In the cold H+MF-L dimers, the ligand forms an OH...L hydrogen bond, while bonding to the positively charged 2pz orbital of the carbonyl C atom is less favorable. The latter allows estimation of the free OH stretch fundamental of the most stable H+MF(t/s) rotamer as 3545 ± 5 cm−1. While for neutral MF the more stable syn rotamer MF(s) dominates the population in both the laboratory and the ISM (>99%), the anti conformer is substantially populated for H+MF (∼30%), which is rationalized by protonation-induced isomerization. This mechanism may lead to an enhanced abundance of MF(a) in certain regions of the ISM. [ABSTRACT FROM AUTHOR]

Galaxy mergers are expected to produce multiple supermassive black holes (SMBHs) in close-separation, but the detection of such SMBHs has been difficult. 2MASS J165939.7 + 183436 is a red active galactic nucleus (AGN) that is a prospective merging SMBH candidate owing to its merging features in Hubble Space Telescope imaging and double-peaked broad emission lines (BELs). Herein, we report a Gemini Multi-Object Spectrograph Integral Field Unit observation of a double-peaked broad Hα line of 2MASS J165939.7+183436. Furthermore, we confirm the existence of two BEL peaks that are kinematically separated by 3000 km s−1, with the SMBH of each BEL component weighing at and , if they arise from independent BELs near the two SMBHs. The BEL components were not separated at >0.″1; however, under several plausible assumptions regarding the fitting of each spaxel, the two components are found to be spatially separated at 0.″085 (∼250 pc). Different assumptions for the fitting can lead to a null (<0.″05) or a larger spatial separation (∼0.″15). Given the uncertainty regarding the spatial separation, various models, such as the disk emitter and multiple SMBH models, are viable solutions to explain the double BEL components. These results will promote future research for finding more multiple SMBH systems in red AGNs, and higher-resolution imaging validates these different models. [ABSTRACT FROM AUTHOR]

Recent integral field spectroscopy observations have found that about 11% of galaxies show star–gas misalignment. The misalignment possibly results from external effects such as gas accretion, interaction with other objects, and other environmental effects, hence providing clues to these effects. We explore the properties of misaligned galaxies using Horizon-AGN, a large-volume cosmological simulation, and compare the results with those of the Sydney-AAO Multi-object integral field spectrograph (SAMI) Galaxy Survey. Horizon-AGN can match the overall misalignment fraction and reproduces the distribution of misalignment angles found by observations surprisingly closely. The misalignment fraction is found to be highly correlated with galaxy morphology both in observations and in the simulation: early-type galaxies are substantially more frequently misaligned than late-type galaxies. The gas fraction is another important factor associated with misalignment in the sense that misalignment increases with decreasing gas fraction. However, there is a significant discrepancy between the SAMI and Horizon-AGN data in the misalignment fraction for the galaxies in dense (cluster) environments. We discuss possible origins of misalignment and disagreement. [ABSTRACT FROM AUTHOR]

We explore the environmental influences on the star formation (SF) in low-mass galaxies with stellar mass 8 ≤ log(M⋆/M⊙) ≤ 10 at a redshift of 0.01 < z < 0.07. We identify the neighboring galaxies for our sample using the spectroscopically observed galaxies in the Sloan Digital Sky Survey (SDSS). Our 287 selected pair candidates have a neighboring galaxy with a stellar mass ratio of MNeighbor/MCandidate ≤ 4 at a projected separation within dproj ≤ 1500 kpc and a line-of-sight kinematic separation of ΔvLOS ≤ 300 km s−1. Our control galaxies are isolated from other galaxies within a projected radius of 1500 kpc. All selected galaxies in our sample are spectroscopically observed by the fourth generation of SDSS/Mapping Nearby Galaxies at Apache Point Observatory (SDSS-IV/MaNGA) integral field spectroscopy survey. We radially bin our selected galaxies into three regions with a radial distance of 0 ≤ R/Re ≤ 0.5 (inner), 0.5 ≤ R/Re ≤ 1.0 (middle), and 1.0 ≤ R/Re ≤ 1.5 (outer), in which Re is the effective radius at where the galaxy emit half of its light. We conclude that the SF activities in low-mass galaxies are affected by their environmental conditions when ΔvLOS ≤ 100 km s−1 at dproj ≤ 400 kpc. We use stellar-mass-weighted SF rate surface density () to describe the SF strength in each radially binned region. For the pair candidates with 0.25 ≤ MNeighbor/MCandidate ≤ 4 at dproj ≤ 100 kpc and , we observe an SF enhancement of (= /) in their inner regions, which decreases with increasing galactic radii. [ABSTRACT FROM AUTHOR]

We use deep adaptive optics assisted integral field spectroscopy from SINFONI on the VLT to study the spatially resolved properties of ionized gas outflows driven by active galactic nuclei (AGNs) in three galaxies at z ∼ 2.2—K20-ID5, COS4-11337, and J0901 + 1814. These systems probe AGN feedback from nuclear to circumgalactic scales and provide unique insights into the different mechanisms by which AGN-driven outflows interact with their host galaxies. K20-ID5 and COS4-11337 are compact star-forming galaxies with powerful ∼1500 km s−1 AGN-driven outflows that dominate their nuclear Hα emission. The outflows do not appear to have any impact on the instantaneous star formation activity of the host galaxies, but they carry a significant amount of kinetic energy that could heat the halo gas and potentially lead to a reduction in the rate of cold gas accretion onto the galaxies. The outflow from COS4-11337 is propagating directly toward its companion galaxy COS4-11363, at a projected separation of 5.4 kpc. COS4-11363 shows signs of shock excitation and recent truncation of star formation activity, which could plausibly have been induced by the outflow from COS4-11337. J0901 + 1814 is gravitationally lensed, giving us a unique view of a compact (R = 470 ± 70 pc), relatively low-velocity (∼650 km s−1) AGN-driven outflow. J0901 + 1814 has a similar AGN luminosity to COS4-11337, suggesting that the difference in outflow properties is not related to the current AGN luminosity and may instead reflect a difference in the evolutionary stage of the outflow and/or the coupling efficiency between the AGN ionizing radiation field and the gas in the nuclear regions. [ABSTRACT FROM AUTHOR]

We present the pilot study of the Fluorescent Lyman-Alpha Structures in High-z Environments Survey; the largest integral field spectroscopy survey to date of the circumgalactic medium at z = 2.3–3.1. We observed 48 quasar fields with the Palomar Cosmic Web Imager to an average (2σ) limiting surface brightness of 6 × 10−18 erg s−1 cm−2 arcsec−2 (in a 1″ aperture and ∼20 Å bandwidth). Extended H i Lyα emission is discovered around 37/48 of the observed quasars, ranging in projected radius from 14 to 55 proper kiloparsecs (pkpc), with one nebula exceeding 100 pkpc in effective diameter. The dimming-adjusted circularly averaged surface brightness profile peaks at 1 × 10−15 erg s−1 cm−2 arcsec−2 at R⊥ ∼ 20 pkpc and integrated luminosities range from 0.4 to 9.4 × 1043 erg s−1. The emission appears to have an eccentric morphology and an average covering factor of ∼30%–40% at small radii. On average, the nebular spectra are redshifted with respect to both the systemic redshift and Lyα peak of the quasar spectrum. The integrated spectra of the nebulae mostly have single- or double-peaked profiles with global dispersions ranging from 143 to 708 km s−1, though the individual Gaussian components of lines with complex shapes mostly have dispersions ≤400 km s−1, and the flux-weighted velocity centroids of the lines vary by thousands of km s−1 with respect to the QSO redshifts. Finally, the root-mean-square velocities of the nebulae are found to be consistent with those expected from gravitational motions in dark matter halos of mass. We compare these results to existing surveys at higher and lower redshift. [ABSTRACT FROM AUTHOR]

The Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST) provides measurements over the wavelength range 5 to 28:5 µm. MIRI has, within a single "package," four key scientific functions: photometric imaging, coronagraphy, single-source low-spectral resolving power (R ~ 100) spectroscopy, and medium-resolving power (R ~ 1500 to 3500) integral field spectroscopy. An associated cooler system maintains MIRI at its operating temperature of <6:7 K. This paper describes the driving principles behind the design of MIRI, the primary design parameters, and their realization in terms of the "as-built" instrument. It also describes the test program that led to delivery of the tested and calibrated Flight Model to NASA in 2012, and the confirmation after delivery of the key interface requirements. [ABSTRACT FROM AUTHOR]

We present new, deep near-infrared SINFONI @ VLT integral field spectroscopy of the gas cloud G2 in the Galactic Center, from late 2013 August, 2014 April, and 2014 July. G2 is visible in recombination line emission. The spatially resolved kinematic data track the ongoing tidal disruption. The cloud reached minimum distance to the MBH of 1950 Schwarzschild radii. As expected for an observation near the pericenter passage, roughly half of the gas in 2014 is found at the redshifted, pre-pericenter side of the orbit, while the other half is at the post-pericenter, blueshifted side. We also present an orbital solution for the gas cloud G1, which was discovered a decade ago in L'-band images when it was spatially almost coincident with Sgr A*. The orientation of the G1 orbit in the three angles is almost identical to that of G2, but it has a lower eccentricity and smaller semi-major axis. We show that the observed astrometric positions and radial velocities of G1 are compatible with the G2 orbit, assuming that (1) G1 was originally on the G2 orbit preceding G2 by 13 yr, and (2) a simple drag force acted on it during pericenter passage. Taken together with the previously described tail of G2, which we detect in recombination line emission and thermal broadband emission, we propose that G2 may be a bright knot in a much more extensive gas streamer. This matches purely gaseous models for G2, such as a stellar wind clump or the tidal debris from a partial disruption of a star. [ABSTRACT FROM AUTHOR]

We present a detailed analysis of multi-wavelength Hubble Space Telescope/Wide Field Camera 3 (WFC3) imaging and Keck/OSIRIS near-infrared adaptive optics-assisted integral field spectroscopy for a highly magnified lensed galaxy at z = 1.70. This young starburst is representative of ultraviolet-selected star-forming galaxies (SFGs) at z ∼ 2 and contains multiple individual star-forming regions. Due to the lensing magnification, we can resolve spatial scales down to 100 pc in the source plane of the galaxy. The velocity field shows disturbed kinematics suggestive of an ongoing interaction and there is a clear signature of a tidal tail. We constrain the age, reddening, star formation rate, and stellar mass of the star-forming clumps from spectral energy distribution (SED) modeling of the WFC3 photometry and measure their Hα luminosity, metallicity, and outflow properties from the OSIRIS data. With strong star-formation-driven outflows in four clumps, RCSGA0327 is the first high-redshift SFG at stellar mass <1010M☼ with spatially resolved stellar winds. We compare the Hα luminosities, sizes, and dispersions of the star-forming regions with other high-z clumps as well as local giant H II regions and find no evidence for increased clump star formation surface densities in interacting systems, unlike in the local universe. Spatially resolved SED modeling unveils an established stellar population at the location of the largest clump and a second mass concentration near the edge of the system that is not detected in Hα emission. This suggests a picture of an equal-mass mixed major merger, which has not triggered a new burst of star formation or caused a tidal tail in the gas-poor component. [ABSTRACT FROM AUTHOR]

We present new Spectrographic Areal Unit for Research on Optical Nebulae (SAURON) integral-field spectroscopy and Swift Ultraviolet Optical Telescope (UVOT) observations of molecular outflow host galaxy NGC 1266 that indicate NGC 1266 has experienced a rapid cessation of star formation. Both the SAURON maps of stellar population age and the Swift UVOT observations demonstrate the presence of young (<1 Gyr) stellar populations within the central 1 kpc, while existing Combined Array for Research in Millimeter-Wave Astronomy CO(1-0) maps indicate that the sites of current star formation are constrained to only the inner few hundred parsecs of the galaxy. The optical spectrum of NGC 1266 from Moustakas & Kennicutt reveal a characteristic poststarburst (K+A) stellar population, and Davis et al. confirm that ionized gas emission in the system originate from a shock. Galaxies with K+A spectra and shock-like ionized gas line ratios may comprise an important, overlooked segment of the poststarburst population, containing exactly those objects in which the active galactic nucleus (AGN) is actively expelling the star-forming material. While AGN activity is not the likely driver of the poststarburst event that occurred 500 Myr ago, the faint spiral structure seen in the Hubble Space Telescope Wide-field Camera 3 Y-, J- and H-band imaging seems to point to the possibility of gravitational torques being the culprit. If the molecular gas were driven into the center at the same time as the larger scale galaxy disk underwent quenching, the AGN might be able to sustain the presence of molecular gas for ≳ 1 Gyr by cyclically injecting turbulent energy into the dense molecular gas via a radio jet, inhibiting star formation. [ABSTRACT FROM AUTHOR]

Using the WiFeS integral field spectrograph, we have undertaken a series of observations of star-forming galaxies in compact groups. In this first paper dedicated to the project, we present the analysis of the spiral galaxy NGC 838, a member of the Hickson Compact Group 16, and of its galactic wind. Our observations reveal that the wind forms an asymmetric, bipolar, rotating structure, powered by a nuclear starburst. Emission line ratio diagnostics indicate that photoionization is the dominant excitation mechanism at the base of the wind. Mixing from slow shocks (up to 20%) increases further out along the outflow axis. The asymmetry of the wind is most likely caused by one of the two lobes of the wind bubble bursting out of its Hi envelope, as indicated by line ratios and radial velocity maps. The characteristics of this galactic wind suggest that it is caught early (a few Myr) in the wind evolution sequence. The wind is also quite different from the galactic wind in the partner galaxy NGC 839 which contains a symmetric, shock-excited wind. Assuming that both galaxies have similar interaction histories, the two different winds must be a consequence of the intrinsic properties of NGC 838 and NGC 839 and their starbursts. [ABSTRACT FROM AUTHOR]

The cores of massive galaxy clusters, where hot gas is cooling rapidly, appear to undergo cycles of self-regulating energy feedback, in which active galactic nucleus (AGN) outbursts in the central galaxies episodically provide sufficient heating to offset much of the gas cooling. We use deep integral-field spectroscopy to study the optical line emission from the extended nebulae of three nearby brightest cluster galaxies and investigate how they are related to the processes of heating and cooling in the cluster cores. Two of these systems, A3581 and Sersic 159-03, appear to be experiencing phases of feedback that are dominated by the activity and output of a central AGN. A3581 shows evidence for significant interaction between the radio outflows and the optical nebula, in addition to accretion flows into the nucleus of the galaxy. X-ray and radio data show that Sersic 159-03 is dominated by the feedback of energy from the central AGN, but the kinematics of the optical nebula are consistent with infall or outflow of material along its bright filaments. The third system, 2A 0335+096, is dominated by mass accretion and cooling, and so we suggest that it is in an accumulation phase of the feedback cycle. The outer nebula forms a disk-like structure, ~14 kpc in radius, that rotates about the central galaxy with a velocity amplitude of ~200 km s-1. Overall, our data are consistent with ongoing AGN-driven feedback cycles occurring in these systems. [ABSTRACT FROM AUTHOR]

We present Keck OSIRIS 1.1-1.8 µm adaptive optics integral field spectroscopy of the planetary-mass companion to GSC 06214-00210, a member of the ~5 Myr Upper Scorpius OB association. We infer a spectral type of L0 ± 1, and our spectrum exhibits multiple signs of youth. The most notable feature is exceptionally strong Paβ emission (EW = - 11.4 ± 0.3 Å), which signals the presence of a circumplanetary accretion disk. The luminosity of GSC 06214-00210 b combined with its age yields a model-dependent mass of 14 ± 2 MJUP, making it the lowest-mass companion to show evidence of a disk. With a projected separation of 320 AU, the formation of GSC 06214-00210 b and other very low mass companions on similarly wide orbits is unclear. One proposed mechanism is formation at close separations followed by planet-planet scattering to much larger orbits. Since that scenario involves a close encounter with another massive body, which is probably destructive to circumplanetary disks, it is unlikely that GSC 06214-00210 b underwent a scattering event in the past. This implies that planet-planet scattering is not solely responsible for the population of gas giants on wide orbits. More generally, the identification of disks around young planetary companions on wide orbits offers a novel method to constrain the formation pathway of these objects, which is otherwise notoriously difficult to do for individual systems. We also refine the spectral type of the primary from MI to K7 and detect a mild (2σ) excess at 22 µm using Wide-Field Infrared Survey Explorer photometry. [ABSTRACT FROM AUTHOR]

We present an integral field spectroscopic study of two nearby luminous infrared galaxies (LIRGs), IC 1623 and NGC 3256, which exhibit evidence of widespread shock excitation induced by ongoing merger activity. We show the importance of carefully separating excitation due to shocks versus excitation by H II regions and the usefulness of integral field unit data in interpreting the complex processes in LIRGs. Our analysis focuses primarily on the emission line gas, which is extensive in both systems and is a result of the abundant ongoing star formation as well as widespread LINER-like excitation from shocks. We use emission line ratio maps, line kinematics, line-ratio diagnostics, and new models as methods for distinguishing and analyzing shocked gas in these systems. We discuss how our results inform the merger sequence associated with local U/LIRGs and the impact that widespread shock excitation has on the interpretation of emission line spectra and derived quantities of both local and high-redshift galaxies. [ABSTRACT FROM AUTHOR]

We present an unbiased spectroscopic study of the Galactic supernova remnant (SNR) Cygnus Loop using the Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) DR5. LAMOST features both a large field of view and a large aperture, which allow us to simultaneously obtain 4000 spectra at ∼3700–9000 Å with R ≈ 1800. The Cygnus Loop is a prototype of middle-aged SNRs, which has the advantages of being bright, large in angular size, and relatively unobscured by dust. Along the line of sight to the Cygnus Loop, 2747 LAMOST DR5 spectra are found in total, which are spatially distributed over the entire remnant. This spectral sample is free of the selection bias of most previous studies, which often focus on bright filaments or regions bright in [O iii]. Visual inspection verifies that 368 spectra (13% of the total) show clear spectral features to confirm their association with the remnant. In addition, 176 spectra with line emission show ambiguity of their origin but have a possible association to the SNR. In particular, the 154 spectra dominated by the SNR emission are further analyzed by identifying emission lines and measuring their intensities. We examine distributions of physical properties such as electron density and temperature, which vary significantly inside the remnant, using theoretical models. By combining a large number of the LAMOST spectra, a global spectrum representing the Cygnus Loop is constructed, which presents characteristics of radiative shocks. Finally, we discuss the effect of the unbiased spectral sample on the global spectrum and its implication to understand a spatially unresolved SNR in a distant galaxy. [ABSTRACT FROM AUTHOR]

The abstraction reaction H + NaH+ (v0 = 0, j0 = 0) → Na+ + H2 and exchange reaction H′ + NaH+ (v0 = 0, j0 = 0) → NaH′+ + H were studied using the time-dependent wave packet method with second order split operator in the collision energy range from 0.01 to 1.0 eV. A new global potential energy surface (PES), which was reported by Yuan and co-workers (2018 Chem. Phys. Lett.700 122), was used in the present dynamics calculation. The dynamics properties such as reaction probability, integral cross section, differential cross section, and the distribution of the product were presented in the present work. The results show that direct abstraction mechanism is dominated in abstraction reaction whereas the ‘rebound’ mechanism plays a dominant role in exchange reaction. [ABSTRACT FROM AUTHOR]

We here present the results of 0.1 pc scale observations in 250 and 350 GHz toward a newly-discovered hot molecular core in a nearby low-metallicity galaxy, the Large Magellanic Cloud (LMC), with the Atacama Large Millimeter/submillimeter Array. A variety of C/N/O/Si/S-bearing molecules are detected toward the high-mass young stellar object, ST16. A rotating protostellar envelope is for the first time detected outside our Galaxy by SO2 and 34SO lines. An outflow cavity is traced by CCH and CN. The isotope abundance of sulfur in the source is estimated to be 32S/34S = 17 and 32S/33S = 53 based on SO, SO2, and CS isotopologues, suggesting that both 34S and 33S are overabundant in the LMC. Rotation diagram analyses show that the source is associated with hot gas (>100 K) traced by high-excitation lines of CH3OH and SO2, as well as warm gas (∼50 K) traced by CH3OH, SO2, 34SO, OCS, and CH3CN lines. A comparison of molecular abundances between LMC and Galactic hot cores suggests that organic molecules (e.g., CH3OH, a classical hot core tracer) show a large abundance variation in low metallicity, where the present source is classified into an organic-poor hot core. Our astrochemical simulations suggest that different grain temperatures during the initial ice-forming stage would contribute to the chemical differentiation. In contrast, SO2 shows similar abundances within all of the known LMC hot cores, and the typical abundance roughly scales with the LMC’s metallicity. Nitrogen-bearing molecules are generally less abundant in the LMC hot cores, except for NO. The present results suggest that chemical compositions of hot cores do not always simply scale with the metallicity. [ABSTRACT FROM AUTHOR]

Offsets of molecular line emission peaks from continuum peaks are very common but frequently difficult to explain with a single spherical cloud chemical model. We propose that the spatial projection effects of an irregular three-dimensional (3D) cloud structure can be a solution. This work shows that the idea can be successfully applied to the Planck cold clump G224.4-0.6 by approximating it with four individual spherically symmetric cloud cores whose chemical patterns overlap with each other to produce observable line maps. With the empirical physical structures inferred from the observation data of this clump and a gas-grain chemical model, the four cores can satisfactorily reproduce its 850 μm continuum map and the diverse peak offsets of CCS, HC3N, and N2H+ simultaneously at chemical ages of about 8 × 105 ∼ 3 × 106 yr. The 3D projection effects on chemistry has the potential to explain such asymmetrical distributions of chemicals in many other molecular clouds. [ABSTRACT FROM AUTHOR]

We present a comprehensive analysis of the multiphase structure of the interstellar medium (ISM) and the stellar kinematics in the edge-on nearby galaxy UGC 10205 using integral field spectroscopy (IFS) data taken with Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía (MEGARA) at the GTC. We explore both the neutral and the ionized gas phases using the interstellar Na i D doublet absorption (LR−V setup, R ∼ 6000) and the Hα emission line (HR−R setup, R ∼ 18000), respectively. The high-resolution data show the complexity of the Hα emission-line profile revealing the detection of up to three kinematically distinct gaseous components. Despite of this fact, a thin-disk model is able to reproduce the bulk of the ionized gas motions in the central regions of UGC 10205. The use of asymmetric drift corrections is needed to reconciliate the ionized and the stellar velocity rotation curves. We also report the detection of outflowing neutral gas material blueshifted by ∼ 87 km s−1. The main physical properties that describe the observed outflow are a total mass Mout = (4.55 ± 0.06) × 107M☉ and a cold-gas mass outflow rate M☉ yr−1. This work points out the necessity of exploiting high-resolution IFS data to understand the multiphase components of the ISM and the multiple kinematical components in the central regions of nearby galaxies. [ABSTRACT FROM AUTHOR]