Search

We present 850 μ m polarization observations of the IC 348 star-forming region in the Perseus molecular cloud as part of the B-fields In STar-forming Region Observation survey. We study the magnetic properties of two cores (HH 211 MMS and IC 348 MMS) and a filamentary structure of IC 348. We find that the overall field tends to be more perpendicular than parallel to the filamentary structure of the region. The polarization fraction decreases with intensity, and we estimate the trend by power law and the mean of the Rice distribution fittings. The power indices for the cores are much smaller than 1, indicative of possible grain growth to micron size in the cores. We also measure the magnetic field strengths of the two cores and the filamentary area separately by applying the Davis–Chandrasekhar–Fermi method and its alternative version for compressed medium. The estimated mass-to-flux ratios are 0.45–2.20 and 0.63–2.76 for HH 211 MMS and IC 348 MMS, respectively, while the ratios for the filament are 0.33–1.50. This result may suggest that the transition from subcritical to supercritical conditions occurs at the core scale (∼0.05 pc) in the region. In addition, we study the energy balance of the cores and find that the relative strength of turbulence to the magnetic field tends to be stronger for IC 348 MMS than for HH 211 MMS. The result could potentially explain the different configurations inside the two cores: a single protostellar system in HH 211 MMS and multiple protostars in IC 348 MMS. [ABSTRACT FROM AUTHOR]

We report the tentative detection of the ring molecule cyclopropenylidene (c -C |$_3$| H |$_2$|⁠) in cometary comae. We observed three short-period comets: 73P/Schwassmann–Wachmann 3, 17P/Holmes, 103P Hartley 2, and two Oort Cloud comets: C/2007 N3 (Lulin) and C/2012 F6 (Lemmon) with the Arizona Radio Observatory Submillimeter Telescope (SMT) and the Atacama Large Millimeter/submillimeter Array (ALMA). We tentatively detected c -C |$_3$| H |$_2$| in three of the comets, with molecule production rates in the range of |$(0.2\!-\!3.8)\times 10^{25}$| molecules s |$^{-1}$|⁠ , and c -C |$_3$| H |$_2$| /H |$_2$| O mixing ratios of 0.01–0.19  per cent. Evidence from both the single-dish and interferometric data points to the presence of c -C |$_3$| H |$_2$| being of a discrete transient nature and exhibiting an extended spatial distribution, indicating production from the decomposition of organic dust particles in the coma. [ABSTRACT FROM AUTHOR]

The Leighton Chajnantor Telescope (LCT) is an international collaborative program among Caltech, Shanghai Normal University (ShNU), and Universidad de Concepción (UdeC), aiming at the refurbishment and relocation of the Caltech Submillimeter Observatory (CSO) telescope from Mauna Kea, Hawaii, to the Chajnantor Plateau, northern Chile. A suite of excellent-sensitivity heterodyne superconductor–insulator–superconductor (SIS) receivers will be deployed to the telescope as the first set of instrumentations for high-resolution spectral observation. However, the current refrigeration technology for this receiver utilizes liquid helium (LHe), which greatly increases the cost of cooling and labor. To address this problem, a new LHe-free cryostat for the LCT heterodyne SIS receiver has been designed, fabricated, and tested. Mechanical and thermal analyses were performed to ensure that the cryostat meets the requirements of the telescope pointing accuracy and the SIS junction working environment, respectively. The experiment testing results are in good agreement with the calculation and analysis, indicating that the proposed LHe-free cryostat meets the operational requirements of the telescope at the new site. [ABSTRACT FROM AUTHOR]

Measuring the environments of massive galaxies at high redshift is crucial to understanding galaxy evolution and the conditions that gave rise to the distribution of matter we see in the Universe today. While high- z radio galaxies (H z RGs) and quasars tend to reside in protocluster-like systems, the environments of their radio-quiet counterparts are relatively unexplored, particularly in the submillimetre, which traces dust-obscured star formation. In this study, we search for 850  μ m-selected submillimetre galaxies (SMGs) in the environments of massive (⁠|$M_{\star }$| |$\gt 10^{11}$| |${\rm M}_{\odot }$|⁠), radio-quiet (⁠|$L_{500 {\rm MHz}}$| |$\lesssim 10^{25}$|  WHz |$^{-1}$|⁠) galaxies at |$z \sim 1\!-\!3$| using data from the SCUBA-2 COSMOS (S2COSMOS) survey. By constructing number counts in circular regions of radius 1–6 arcmin and comparing with blank-field measurements, we find no significant overdensities of SMGs around massive radio-quiet galaxies at any of these scales, despite being sensitive down to overdensities of |$\delta \sim 0.4$|⁠. To probe deeper than the catalogue we also examine the distribution of peaks in the SCUBA-2 signal-to-noise (SNR) map, which reveals only tentative signs of any difference in the SMG densities of the radio-quiet galaxy environments compared to the blank field, and only on smaller scales (1 arcmin radii, corresponding to |$\sim 0.5$|  Mpc) and higher SNR thresholds. We conclude that massive, radio-quiet galaxies at cosmic noon are typically in environments with |$\delta \lesssim 0.4$|⁠ , which are either consistent with the blank field or contain only weak overdensities spanning sub-Mpc scales. The contrast between our results and studies of H z RGs with similar stellar masses and redshifts implies an intrinsic link between the wide-field environment and the radio luminosity of the active galactic nucleus at high redshift. [ABSTRACT FROM AUTHOR]

We present Atacama Large Millimetre/submillimetre Array (ALMA) observations of the [O  iii ] 88  |$\mu {\rm m}$| emission of a sample of thirteen galaxies at |$z = 6$| to 7.6 selected as [C  ii ]-emitting companion sources of quasars. To disentangle the origins of the luminous Oxygen line in the |$z\, \gt\, 6$| Universe, we looked at emission-line galaxies that are selected through an excellent star-formation tracer [C  ii ] with star-formation rates between 9 and 162  |$\rm {\rm M}_{\odot }\,yr^{-1}$|⁠. Direct observations reveal [O  iii ] emission in just a single galaxy (⁠|$L_\mathrm{[O\, {\small III}]}/L_\mathrm{[C\, {\small II}]}$| |$\, = 2.3$|⁠), and a stacked image shows no [O  iii ] detection, providing deep upper limits on the |$L_\mathrm{[O\, {\small III}]}/L_\mathrm{[C\, {\small II}]}$| ratios in the |$z \gt 6$| Universe (⁠|$L_\mathrm{[O\, {\small III}]}/L_\mathrm{[C\, {\small II}]}$| |$\, \lt 1.2$| at |$3 \sigma$|⁠). While the fidelity of this sample is high, no obvious optical/near-infrared counterpart is seen in the JWST imaging available for four galaxies. Additionally accounting for low- z CO emitters, line stacking shows that our sample-wide result remains robust: The enhanced |$L_\mathrm{[O\, {\small III}]}/L_\mathrm{[C\, {\small II}]}$| reported in the first billion years of the Universe is likely due to the selection towards bright, blue Lyman-break galaxies with high surface star-formation rates or young stellar populations. The deep upper limit on the rest-frame 90  μ m continuum emission (⁠|$\lt 141 \mu$| Jy at |$3 \sigma$|⁠), implies a low average dust temperature (⁠|$T_\mathrm{dust} \lesssim 30\,$|  K) and high-dust mass (⁠|$M_\mathrm{dust} \sim 10^8\, \mathrm{M}_\odot$|⁠). As more normal galaxies are explored in the early Universe, synergy between JWST and ALMA is fundamental to further investigate the ISM properties of the a broad range of samples of high- z galaxies. [ABSTRACT FROM AUTHOR]

Context. CF+ has been established as a valuable diagnostic tool for investigating photodissociation regions (PDRs) and fluorine abundances in the Milky Way. However, its role in extragalactic environments remains largely uncharted. Aims. Our objective is to explore the significance of CF+ in the Large Magellanic Cloud (LMC) and assess its utility as a probe for examining C+ and fluorine abundances in external galaxies. Methods. We performed pointed CF+ observations toward an active star-forming region, N113 in the LMC, using the Atacama Pathfinder EXperiment 12 m submillimeter telescope. Results. We report the first discovery of CF+ in the LMC through the successful detection of the CF+ (2→1) and (3→2) lines. The excitation models indicate that CF+ emission originates from dense PDRs characterized by an H2 number density of (0.5–7.9) × 104 cm−3 in N113. Our observations provide the first constraint on the fluorine abundance in molecular clouds in the LMC, ≲1.7 × 10−9. This value is about an order of magnitude lower than those previously measured toward red giants in the LMC, indicative of fluorine deficiency in the molecular gas. The estimated column density ratio between C+ and CF+ appears to be lower than the anticipated equilibrium ratio derived from the fluorine abundance in red giants. Both phenomena can be explained by the deficiency of CF+ caused by the freeze-out of its primary chemical precursor, HF, onto dust grains. Conclusions. The deficiency of CF+ within molecular clouds suggests that the measurements presented in this work serve exclusively as conservative estimates, establishing lower bounds for both the fluorine abundance and C+ column densities in external galaxies. [ABSTRACT FROM AUTHOR]

We apply the 3D dust radiative transfer code skirt to the low-redshift (z ≤ 0.1) galaxy population in the TNG100 cosmological simulation, the fiducial run of the IllustrisTNG project. We compute global fluxes and spectral energy distributions (SEDs) from the far-ultraviolet to the submillimetre for |$\approx 60\, 000$| galaxies, with the same post-processing methodology that was previously applied to the TNG50 simulation. We verify that TNG100 reproduces observational luminosity functions at low redshifts to excellent precision, unlike TNG50. Additionally, we test the realism of our TNG100 plus skirt fluxes by comparing various flux and colour relations to data from the GAMA survey. TNG100 broadly reproduces the observed distributions, but we predict ultraviolet colours that are too blue by |$\approx 0.4\, \mathrm{mag}$|⁠ , possibly related to the extinction in the star-forming regions subgrid model not being selective enough. Furthermore, we find that the simulated galaxies exhibit mid-infrared fluxes elevated by up to |$\approx 0.5\, \mathrm{mag}$| that we attribute to overly effective stochastic heating of the diffuse dust. All synthetic broad-band fluxes and SEDs are made publicly available in three orientations and four apertures, and can readily be used to study TNG100 galaxies in a mock observational fashion. [ABSTRACT FROM AUTHOR]

We are studying and developing high-performance spectroscopy solutions in silicon technology in the framework of instrumental developments around the B-BOP bolometer arrays and in the continuation of the former developments of the Herschel space telescope instruments and in particular its photodetector array camera and spectrometer. The integration of multiwavelength spectroscopic capabilities close to the array of a cooled bolometer would make it possible to detect the interstellar medium continuum by scanning and to trace its evolution, particularly by the detection of characteristic lines such as the cooling line [CII] at 158 µm. In this paper, we present the first concept under development and the preliminary results obtained from our cryogenic optical test bench. This solution is a tunable Fabry–Perot cavity with silicon mirrors driven by a cryogenic piezoelectric mechanism with a nanometric step. Each mirror is a dielectric Bragg structure, a stack of quarter-wave layers of silicon and air providing high reflectivity without metal loss. This solution allows extremely accurate scanning around a targeted wavelength. The first prototype cannot be integrated on a focal plane as it stands, and future optimizations integrating miniaturized scanning systems will make the system much more compact. [ABSTRACT FROM AUTHOR]

Characterization of the magnetic fields at different scales in the Universe is a new frontier for submillimeter astronomy. Polarimetric measurements between 50 and 500 µm are the golden path for this research. We develop, in the prospect of space observatories, all-silicon 50 mK bolometer arrays with polarimetric capabilities in the pixel. Here, we present the first results of the new detectors: performances of thermal sensors, optical absorption and polarimetry. [ABSTRACT FROM AUTHOR]

Very long baseline interferometry (VLBI) provides the highest-resolution images in astronomy. The sharpest resolution is nominally achieved at the highest frequencies, but as the observing frequency increases, so too does the atmospheric contribution to the system noise, degrading the sensitivity of the array and hampering detection. In this paper, we explore the limits of high-frequency VLBI observations using ngehtsim, a new tool for generating realistic synthetic data. ngehtsim uses detailed historical atmospheric models to simulate observing conditions, and it employs heuristic visibility detection criteria that emulate single- and multifrequency VLBI calibration strategies. We demonstrate the fidelity of ngehtsim's predictions using a comparison with existing 230 GHz data taken by the Event Horizon Telescope (EHT), and we simulate the expected performance of EHT observations at 345 GHz. Though the EHT achieves a nearly 100% detection rate at 230 GHz, our simulations indicate that it should expect substantially poorer performance at 345 GHz; in particular, observations of M87* at 345 GHz are predicted to achieve detection rates of ≲20% that may preclude imaging. Increasing the array sensitivity through wider bandwidths and/or longer integration times—as enabled through, e.g., the simultaneous multifrequency upgrades envisioned for the next-generation EHT—can improve the 345 GHz prospects and yield detection levels that are comparable to those at 230 GHz. M87* and Sgr A* observations carried out in the atmospheric window around 460 GHz could expect to regularly achieve multiple detections on long baselines, but analogous observations at 690 and 875 GHz consistently obtain almost no detections at all. [ABSTRACT FROM AUTHOR]

Atacama Large Millimetre/submillimetre Array (ALMA) observations of the thermal emission from protoplanetary disc dust have revealed a wealth of substructures that could evidence embedded planets, but planet-driven spirals, one of the more compelling lines of evidence, remain relatively rare. Existing works have focused on detecting these spirals using methods that operate in image space. Here, we explore the planet detection capabilities of fitting planet-driven spirals to disc observations directly in visibility space. We test our method on synthetic ALMA observations of planet-containing model discs for a range of disc/observational parameters, finding it significantly outperforms image residuals in identifying spirals in these observations and is able to identify spirals in regions of the parameter space in which no gaps are detected. These tests suggest that a visibility-space fitting approach warrants further investigation and may be able to find planet-driven spirals in observations that have not yet been found with existing approaches. We also test our method on six discs in the Taurus molecular cloud observed with ALMA at 1.33 mm, but find no evidence for planet-driven spirals. We find that the minimum planet masses necessary to drive detectable spirals range from ≈0.03 to |$0.5 \, M_{\text{Jup}}$| over orbital radii of 10–100 au, with planet masses below these thresholds potentially hiding in such disc observations. Conversely, we suggest that planets ≳0.5–1  M Jup can likely be ruled out over orbital radii of ≈20– |$60 \, \text{au}$| on the grounds that we would have detected them if they were present. [ABSTRACT FROM AUTHOR]

We present JWST and Atacama Large Millimeter/submillimeter Array (ALMA) imaging for the lensing system SPT0418−47, which includes a strongly lensed, dusty, star-forming galaxy at redshift z = 4.225 and an associated multiply imaged companion. The JWST NIRCam and MIRI imaging observations presented in this paper were acquired as part of the Early Release Science program Targeting Extremely Magnified Panchromatic Lensed Arcs and Their Extended Star formation (TEMPLATES). This data set provides robust mutiwavelength detections of stellar light in both the main (SPT0418A) and companion (SPT0418B) galaxies, while the ALMA detection of [C ii ] emission confirms that SPT0418B lies at the same redshift as SPT0418A. We infer that the projected physical separation of the two galaxies is 4.42 ± 0.05 kpc. We derive total magnifications of μ = 29 ± 1 and μ = 4.1 ± 0.7 for SPT0418A and SPT0418B, respectively. We use both prospector and cigale to derive stellar masses. We find that SPT0418A has a stellar mass of M * = 3.4 − 0.6 + 1.1 × 10 10 M ⊙ from prospector or M * = 1.5 ± 0.3 × 1010 M ⊙ from cigale. The stellar mass ratio of SPT0418A and SPT0418B is roughly between 4 and 7 ( 4.2 − 1.6 + 1.9 for prospector and 7.5 ± 3.7 for cigale). We see evidence of extended structure associated with SPT0418A that is suggestive of a tidal feature. These features, along with the close projected proximity, imply that the system is interacting. Interestingly, the star formation rates and stellar masses of both galaxies are consistent with the main sequence of star-forming galaxies at this epoch, indicating that this ongoing interaction has not noticeably elevated the star formation levels. [ABSTRACT FROM AUTHOR]

We investigate the constraints provided by the Euclid space observatory on the physical properties of dusty star-forming galaxies (DSFGs) at |$z\gtrsim 1.5$| detected in wide area submillimetre surveys with Herschel. We adopt a physical model for the high- z progenitors of spheroidal galaxies, which form the bulk of DSFGs at |$z\gtrsim 1.5$|⁠. We improve the model by combining the output of the equations of the model with a formalism for the spectral energy distribution (SED). After optimizing the SED parameters to reproduce the measured infrared luminosity function and number counts of DFSGs, we simulated a sample of DSFGs over 100  |$\hbox{deg}^2$| and then applied a |$5\, \sigma$| detection limit of |$37\,$|  mJy at 250  |$\mu$| m. We estimated the redshifts from the Euclid data and then fitted the Euclid + Herschel photometry with the code CIGALE to extract the physical parameters. We found that 100 per cent of the Herschel galaxies are detected in all 4 Euclid bands above |$3\, \sigma$|⁠. For 87 per cent of these sources the accuracy on |$1 + z$| is better than 15 per cent. The sample comprises mostly massive, i.e. |$\log (M_{\star }/{\rm M}_{\odot })\sim 10.5{\!-\!}12.9$|⁠ , highly star forming, i.e. |$\log (\hbox{SFR}/{\rm M}_{\odot }\hbox{yr}^{-1})\sim 1.5{\!-\!}4$|⁠ , dusty, i.e. |$\log (M_{\rm dust}/{\rm M}_{\odot })\sim 7.5{\!-\!}9.9$|⁠ , galaxies. The measured stellar masses have a dispersion of 0.19 dex around the true value, thus showing that Euclid will provide reliable stellar mass estimates for the majority of the bright DSFGs at |$z\gtrsim 1.5$| detected by Herschel. We also explored the effect of complementing the Euclid photometry with that from the Vera C. Rubin Observatory/LSST. [ABSTRACT FROM AUTHOR]

Context. Galaxy submillimetre number counts are a fundamental measurement in our understanding of galaxy evolution models. Most early measurements are obtained via single-dish telescopes with substantial source confusion, whereas recent interferometric observations are limited to small areas. Aims. We used a large database of ALMA continuum observations to accurately measure galaxy number counts in multiple (sub)millimetre bands, thus bridging the flux density range between single-dish surveys and deep interferometric studies. Methods. We continued the Automated Mining of the ALMA Archive in the COSMOS Field project (A3COSMOS) and extended it with observations from the GOODS-South field (A3GOODSS). The database consists of ∼4000 pipeline-processed continuum images from the public ALMA archive, yielding 2050 unique detected sources, including sources with and without a known optical counterpart. To infer galaxy number counts, we constructed a method to reduce the observational bias inherent to targeted pointings that dominate the database. This method comprises a combination of image selection, masking, and source weighting. The effective area was calculated by accounting for inhomogeneous wavelengths, sensitivities, and resolutions and for the spatial overlap between images. We tested and calibrated our method with simulations. Results. We derived the number counts in a consistent and homogeneous way in four different ALMA bands covering a relatively large area. The results are consistent with number counts retrieved from the literature within the uncertainties. In Band 7, at the depth of the inferred number counts, ∼40% of the cosmic infrared background is resolved into discrete sources. This fraction, however, decreases with increasing wavelength, reaching ∼4% in Band 3. Finally, we used the number counts to test models of dusty galaxy evolution, and find a good agreement within the uncertainties. Conclusions. By continuing the A3COSMOS and A3GOODSS archival effort, we obtained the deepest archive-based (sub)millimetre number counts measured to date over such a wide area. This database proves to be a valuable resource that, thanks to its substantial size, can be used for statistical analyses after having applied certain conservative restrictions. [ABSTRACT FROM AUTHOR]

Context. The mass loss experienced on the asymptotic giant branch (AGB) at the end of the lives of low- and intermediate-mass stars is widely accepted to rely on radiation pressure acting on newly formed dust grains. Dust formation happens in the extended atmospheres of these stars, where the density, velocity, and temperature distributions are strongly affected by convection, stellar pulsation, and heating and cooling processes. The interaction between these processes and how that affects dust formation and growth is complex. Hence, characterising the extended atmospheres empirically is paramount to advance our understanding of the dust formation and wind-driving processes. Aims. We aim to determine the density, temperature, and velocity distributions of the gas in the extended atmosphere of the AGB star R Dor. Methods. We acquired observations using ALMA towards R Dor to study the gas through molecular line absorption and emission. We modelled the observed 12CO v = 0,  J = 2 − 1, v = 1,  J = 2 − 1, and 3 − 2 and 13CO v = 0,  J = 3 − 2 lines using the 3D radiative transfer code LIME to determine the density, temperature, and velocity distributions up to a distance of four times the radius of the star at sub-millimetre wavelengths. Results. The high angular resolution of the sub-millimetre maps allows for even the stellar photosphere to be spatially resolved. By analysing the absorption against the star, we infer that the innermost layer in the near-side hemisphere is mostly falling towards the star, while gas in the layer above that seems to be mostly outflowing. Interestingly, the high angular resolution of the ALMA Band 7 observations reveal that the velocity field of the gas seen against the star is not homogenous across the stellar disc. The gas temperature and density distributions have to be very steep close to the star to fit the observed emission and absorption, but they become shallower for radii larger than ∼1.6 times the stellar sub-millimetre radius. While the gas mass in the innermost region is hundreds of times larger than the mass lost on average by R Dor per pulsation cycle, the gas densities just above this region are consistent with those expected based on the mass-loss rate and expansion velocity of the large-scale outflow. Our fits to the line profiles require the velocity distribution on the far side of the envelope to be mirrored, on average, with respect to that on the near side. Using a sharp absorption feature seen in the CO v = 0,  J = 2 − 1 line, we constrained the standard deviation of the stochastic velocity distribution in the large-scale outflow to be ≲0.4 km s−1. We characterised two blobs detected in the CO v = 0,  J = 2 − 1 line and found densities substantially larger than those of the surrounding gas. The two blobs also display expansion velocities that are high relative to that of the large-scale outflow. Monitoring the evolution of these blobs will lead to a better understanding of the role of these structures in the mass-loss process of R Dor. [ABSTRACT FROM AUTHOR]

We present results of dust continuum and [C  ii ] |$\, 158\, {\rm \mu m}$| emission line observations of a remarkably UV luminous (M UV = −21.6) galaxy at z = 10.603: GN-z11. Using the Northern Extended Millimeter Array (NOEMA), observations have been carried out over multiple observing cycles. We achieved a high sensitivity resulting in a |$\lambda _{\rm rest}=160\, {\rm \mu m}$| continuum |$1\, \sigma$| sensitivity of |$13.0\, \rm {\mu Jy \, beam}^{ -1}$| and a [C  ii ] emission line |$1\, \sigma$| sensitivity of |$31\, \rm {mJy\, beam^{ -1}\, km \, s}^{ -1}$| using |$50\, \rm {km \, s}^{ -1}$| binning with a |$\sim 2\, {\rm arcsec}$| synthesized beam. Neither dust continuum nor [C  ii ] |$\, 158\, {\rm \mu m}$| line emission are detected at the expected frequency of ν[C ii ] |$= 163.791\, \rm {GHz}$| and the sky location of GN-z11. The upper limits show that GN-z11 is neither luminous in L IR nor L [C ii ], with a dust mass |$3\, \sigma$| limit of |${\rm log}\, (M_{\rm dust}/{\rm {\rm M}_{\odot }}) \, \lt\, 6.5-6.9$| and with a [C  ii ] based molecular gas mass |$3\, \sigma$| limit of log (M mol, [C ii ] |$/{\rm {\rm M}_{\odot }}) \, \lt \, 9.3$|⁠. Together with radiative transfer calculations, we also investigated the possible cause of the dust poor nature of the GN-z11 showed by the blue colour in the UV continuum of GN-z11 (βUV = −2.4), and found that ≳3 × deeper observations are crucial to study dust production at very high-redshift. Nevertheless, our observations show the crucial role of deep mm/submm observations of very high-redshift galaxies to constrain multiple phases in the interstellar medium. [ABSTRACT FROM AUTHOR]

Sub/millimeter galaxies are a key population for the study of galaxy evolution because the majority of star formation at high redshifts occurred in galaxies deeply embedded in dust. To search for this population, we have performed an extensive survey with Atacama Large Millimeter/submillimeter Array (ALMA), called the ALMA Lensing Cluster Survey (ALCS). This survey covers 133 arcmin2 area and securely detects 180 sources at z ∼ 0.5–6 with a flux limit of ∼0.2 mJy at 1.2 mm. Here, we report the results of multiwavelength spectral energy distribution analysis of the whole ALCS sample, utilizing the observed-frame UV to millimeter photometry. We find that the majority of the ALCS sources lie on the star-forming main sequence, with a smaller fraction showing intense starburst activities. The ALCS sample contains high infrared-excess sources ( IRX = log (L dust / L UV) > 1 ), including two extremely dust-obscured galaxies (IRX > 5). We also confirm that the ALCS sample probes a broader range in lower dust mass than conventional submillimeter galaxy samples in the same redshift range. We identify six heavily obscured active galactic nucleus (AGN) candidates that are not detected in the archival Chandra data in addition to the three X-ray AGNs reported by Uematsu et al. (2023). The inferred AGN luminosity density shows a possible excess at z = 2–3 compared with that determined from X-ray surveys below 10 keV. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the benefits of teaming up data from the radio to the far-infrared (FIR) regime for the characterization of dusty star-forming galaxies (DSFGs). These galaxies are thought to be the star-forming progenitors of local massive quiescent galaxies and to play a pivotal role in the reconstruction of the cosmic star formation rate density up to high redshift. Due to their dust-enshrouded nature, DSFGs are often invisible in the near-infrared/optical/UV bands. Therefore, they necessitate observations at longer wavelengths, primarily the FIR band, where dust emission occurs, and the radio band, which is not affected by dust absorption. Combining data from these two spectral windows makes it possible to characterize even the dustiest objects, enabling the retrieval of information about their age, dust temperature, and star-formation status, and facilitates the differentiation between various galaxy populations that evolve throughout cosmic history. Despite the detection of faint radio sources being a challenging task, this study demonstrates that an effective strategy to build statistically relevant samples of DSFGs would be reaching deep sensitivities in the radio band, even restricted to smaller areas, and then combining these radio observations with FIR/submm data. Additionally, this paper quantifies the improvement in the spectral energy distribution (SED) reconstruction of DSFGs by incorporating ALMA band measurements, in particular, in its upgraded status thanks to the anticipated Wideband Sensitivity Upgrade. [ABSTRACT FROM AUTHOR]

The Caltech Submillimeter Observatory telescope was completely disassembled in 2023 October and will be shipped from Hawaii, USA to the new site at Chajnantor Plateau, Chile in 2024, where it is expected to be refurbished and renamed the Leighton Chajnantor Telescope (LCT). Since the much stronger wind load at the new site will provide a great challenge for LCT's realization of a higher pointing and tracking accuracy, an active disturbance rejection controller (ADRC) is designed for LCT's pointing control system. Due to the unavailability of LCT during its relocation process, it is necessary to develop a testbed to verify the performance of ADRC by constructing a synthesized simulation model of LCT's pointing control system, including a mechanical dynamics model of the antenna, an analog circuit model of the motor drive system, a mathematical model of the direct current motors and the reducers, and a wind disturbance model. On the testbed, ADRC undergoes simulations to verify its capability to eliminate the negative impact of strong wind disturbance on LCT's pointing control performance. The simulation results show that ADRC can bring benefits in improving LCT's pointing and tracking accuracy when facing strong wind disturbance. [ABSTRACT FROM AUTHOR]

We estimate how the mean density of dust in the Universe varies with redshift, using submillimetre continuum observations and a method designed to minimize the effect of dust temperature. We have used the Herschel Astrophysical Terahertz Large Area Survey (Herschel -ATLAS) to show that the median temperature of dust in galaxies is |$\simeq 22\ \mathrm{ K}$| and does not vary significantly with redshift out to z  = 1. With this as our estimate of the mass-weighted dust temperature, we have used an 850- μ m survey of the field of the Cosmological Evolution Survey (COSMOS) to estimate the mean density of dust in 10 redshift bins over the range 0 < z < 5.5. We find that the mean density of dust increased by a factor of ≃10 from z  = 5 to z  = 2, declined slightly to z  = 1, and then steeply to the present day. The relationship between the mean density of dust and redshift is similar to the relationship between the mean star formation rate and redshift, although the increase for the former is steeper from z  = 5 to z  = 2. We have also used the submillimetre measurements to estimate the mean density of gas over the same redshift range. The values we estimate for the dust-traced gas are much lower and with a different redshift dependence than those for estimates of the mean density of atomic gas but similar to those for estimates of the mean density of the CO-traced gas. We find that the depletion time for the dust-traced gas in the Universe as a whole declines with redshift in the same way as seen for individual galaxies. [ABSTRACT FROM AUTHOR]

We derived the dust-to-H  i ratio of the intermediate-velocity clouds (IVCs), the high-velocity clouds (HVCs), and the local H  i gas, by carrying out a multiple-regression analysis of the 21 cm H  i emission combined with the sub-mm dust optical depth. The method covers over 80 per cent of the sky contiguously at a resolution of 47 arcmin and is distinguished from the absorption-line measurements toward bright galaxies and stars covering a tiny fraction of the sky. Major results include that the ratio of the IVCs is in a range of 0.1–1.5 with a mode at 0.6 (relative to the solar-neighbourhood value, likewise below) and that a significant fraction, ∼20 per cent, of the IVCs include dust-poor gas with a ratio of <0.5. It is confirmed that 50 per cent of the HVC Complex C has a ratio of <0.3, and that the Magellanic Stream has the lowest ratio with a mode at ∼0.1. The results prove that some IVCs have low metallicity gas, contrary to the previous absorption-line measurements. Considering that the recent works show that the IVCs are interacting and exchanging momentum with the high-metallicity Galactic halo gas, we argue that the high-metallicity gas contaminates a significant fraction of the IVCs. Accordingly, we argue that the IVCs include a significant fraction of the low-metallicity gas supplied from outside the Galaxy as an alternative to the Galactic-fountain model. [ABSTRACT FROM AUTHOR]

We have carried out Hubble Space Telescope (HST) snapshot observations at 1.1 μm of 281 candidate strongly lensed galaxies identified in the wide-area extragalactic surveys conducted with the Herschel Space Observatory. Our candidates comprise systems with flux densities at |$500\, \mu$| m, S 500 ≥ 80 mJy. We model and subtract the surface brightness distribution for 130 systems, where we identify a candidate for the foreground lens candidate. After combining visual inspection, archival high-resolution observations, and lens subtraction, we divide the systems into different classes according to their lensing likelihood. We confirm 65 systems to be lensed. Of these, 30 are new discoveries. We successfully perform lens modelling and source reconstruction on 23 systems, where the foreground lenses are isolated galaxies and the background sources are detected in the HST images. All the systems are successfully modelled as a singular isothermal ellipsoid. The Einstein radii of the lenses and the magnifications of the background sources are consistent with previous studies. However, the background source circularized radii (between 0.34 and 1.30 kpc) are ∼3 times smaller than the ones measured in the sub-millimetre/millimetre for a similarly selected and partially overlapping sample. We compare our lenses with those in the Sloan Lens Advanced Camera for Surveys (ACS) Survey confirming that our lens-independent selection is more effective at picking up fainter and diffuse galaxies and group lenses. This sample represents the first step towards characterizing the near-infrared properties and stellar masses of the gravitationally lensed dusty star-forming galaxies. [ABSTRACT FROM AUTHOR]

We have used data from the Outer Galaxy High-Resolution Survey (OGHReS) to refine the velocities, distances, and physical properties of a large sample of 3584 clumps detected in far-infrared/submillimetre emission in the Hi-GAL survey located in the ℓ = 250°–280° region of the Galactic plane. Using 12CO and 13CO spectra, we have determined reliable velocities to 3412 clumps (95 per cent of the sample). In comparison to the velocities from the Hi-GAL catalogue, we find good agreement for 80 per cent of the sample (within 5 km s−1). Using the higher resolution and sensitivity of OGHReS has allowed us to correct the velocity for 632 clumps and provide velocities for 687 clumps for which no velocity had been previously allocated. The velocities are used with a rotation curve to refine the distances to the clumps and to calculate the clumps' properties using a distance-dependent gas-to-dust ratio. We have determined reliable physical parameters for 3200 outer Galaxy dense clumps (∼90 per cent of the Hi-GAL sources in the region). We find a trend of decreasing luminosity-to-mass ratio with increasing Galactocentric distance, suggesting the star formation efficiency is lower in the outer Galaxy or that it is resulting in more lower mass stars than in the inner Galaxy. We also find a similar surface density for protostellar clumps located in the inner and outer Galaxy, revealing that the surface density requirements for star formation are the same across the Galactic disc. [ABSTRACT FROM AUTHOR]

One of the most important tasks of studying seeing conditions of possible locations for the Eurasian Submillimeter Telescopes is to research the statistics of precipitated water vapor, optical depth and cloudiness. In this paper, the statistics of precipitated water vapor and total cloudiness in northern Eurasia are studied using ERA-5 reanalysis. Optical depth statistics at a wavelength of 3 mm were obtained using the Liebe model from the ERA-5 reanalysis for the region where the Large Altazimuth Telescope BTA is located. The most favorable astroclimatic zones of Eurasia, along with Tibet and the eastern Pamirs, are certain areas of the Sayan Mountains, mountainous Altai and mountainous Dagestan. The work verifies the ERA-5 reanalysis data using radiosounding, GNSS measurement data and radiometric measurements for 2021. [ABSTRACT FROM AUTHOR]

The determination of reference points for telescopes is crucial for obtaining the local‐tie vector for a multi‐technology co‐located station. Traditional methods suffer from labor‐intensive fieldwork, long execution cycles, and systematic errors due to the incident angle of the total station's laser beam on the prism. In this paper, we propose an algorithm aligning the prism pointing vector with the prism‐to‐total station vector and introduce a pan‐tilt platform and the Tianma VGOS telescope for sub‐millimeter unmanned reference point monitoring. Our results show that the prototype system based on the pan‐tilt achieves a formal error of ±100 μm (1σ) in reference point positions with just 2.5 hr of automated monitoring. The consistency of reference point positions is comparable to the local control network accuracy. Single‐direction observations may introduce a deviation of ±1 mm in the reference point compared to multiple direction observations. Preliminary experiments on the Tianma VGOS telescope have also shown that this system can efficiently automate the monitoring of prism scatter points (one measurement every minute) and achieve sub‐millimeter horizontal precision in reference point positions within a single day. Key Points: A unique algorithm that aligns the prism pointing vector with the prism‐to‐total station vector was derivedAn automatic sub‐millimeter unmanned reference point monitoring prototype is designed and applied to the VGOS telescopeReference point coordinates solved by data sets from multiple directions are evaluated [ABSTRACT FROM AUTHOR]

Bright galaxies at submillimetre wavelengths from Herschel are now well known to be predominantly strongly gravitationally lensed. The same models that successfully predicted this strongly lensed population also predict about 1 per cent of faint 450 μm-selected galaxies from deep James Clerk Maxwell Telescope (JCMT) surveys will also be strongly lensed. Follow-up ALMA campaigns have so far found one potential lens candidate, but without clear compelling evidence, for example, from lensing arcs. Here, we report the discovery of a compelling gravitational lens system confirming the lensing population predictions, with a z s = 3.4 ± 0.4 submm source lensed by a z spec = 0.360 foreground galaxy within the COSMOS field, identified through public JWST imaging of a 450 μm source in the SCUBA-2 Ultra Deep Imaging EAO Survey (STUDIES) catalogue. These systems will typically be well within the detectable range of future wide-field surveys such as Euclid and Roman , and since submillimetre galaxies are predominantly very red at optical/near-infrared wavelengths, they will tend to appear in near-infrared channels only. Extrapolating to the Euclid -Wide survey, we predict tens of thousands of strongly lensed near-infrared galaxies. This will be transformative for the study of dusty star-forming galaxies at cosmic noon, but will be a contaminant population in searches for strongly lensed ultra-high-redshift galaxies in Euclid and Roman. [ABSTRACT FROM AUTHOR]

Models derived in 2009 to fit mid-infrared (8–24 micron) source counts from the IRAS, ISO, and Spitzer missions, provide an excellent fit to deep counts with JWST , demonstrating that the evolution of dusty star-forming galaxies is well understood. The evolution of dust in galaxies at high redshifts is discussed and a simple prescription is proposed to model this. This allows more realistic models for source-counts at submillimetre wavelength. A reasonable fit to 250, 500, 850, and 1100 micron counts is obtained. This paper therefore draws together the IRAS, ISO, Spitzer, Akari, Herschel , submillimetre ground-based, and JWST surveys into a single picture. [ABSTRACT FROM AUTHOR]

The circumgalactic medium (CGM) is a crucial component of galaxy evolution, but thus far its physical properties are highly unconstrained. As of yet, no cosmological simulation has reached convergence when it comes to constraining the cold and dense gas fraction of the CGM. Such components are also challenging to observe directly, as they require sub-millimetre (sub-mm) instruments with a high sensitivity to extended and mostly diffuse emission. We present a state-of-the-art theoretical effort at modelling the [CII] 158 μm, [CI](1−0) 609 μm, [CI](2−1) 370 μm, CO(3−2) 867 μm, and [OIII] 88 μm line emissions that arise from the interstellar medium (ISM) and CGM of galaxies, with the goal of studying the contribution from different cold (T < 104 K) components of galaxy halos. We used the high-resolution cosmological zoom-in simulation PONOS (mgas = 883.4 M⊙), which represents a typical star-forming galaxy system at z = 6.5, composed of a main disc with stellar mass M* = 2 × 109 M⊙ that is undergoing a major merger. We adopted different modelling approaches based on the photoionisation code CLOUDY. Our fiducial model uses radiative transfer post-processing with RAMSES-RT and KROME (KRAMSES-RT) to create more realistic far-ultraviolet (FUV) radiation fields, which we then compared to other sub-grid modelling approaches adopted in the literature. We find significant differences in the luminosity and in the contribution of different gas phases and galaxy components between the different modelling approaches. [CII] is the least model-dependant gas tracer, while [CI](1−0) and CO(3−2) are very model-sensitive. In all models, we find a significant contribution to the emission of [CII] (up to ∼10%) and [OIII] (up to ∼21%) from the CGM. Our fiducial global radiative transfer (RT) model produces a lower density, T ∼ 104 K tail of [CII] emission that is not seen in the other more simplistic models and that resides entirely in the CGM, ionised by the FUV background and producing the extended halos observed in [CII] at high-z. Notably, [CII] and [OIII] trace different regions of the CGM: [CII] arises from an accreting filament and from the tidal tails connecting the main disc and its merging satellites, while [OIII] traces a puffy halo surrounding the main disc, probably linked to supernova feedback. We discuss our results in the context of sub-mm observations. Using simulated spectra and mock maps, we show that, despite the rather compact angular extent of PONOS's CGM, deep ALMA observations would not detect this component, even in [CII] which is the brightest available tracer. Instead, a next generation single-dish observatory such as the Atacama Large Aperture Submillimeter Telescope (AtLAST) could detect PONOS' CGM in [CII] at a high signal-to-noise ratio, and possibly even in [OIII]. [ABSTRACT FROM AUTHOR]

Submillimeter observations reveal the star formation activity obscured by dust in the young Universe. It still remains unclear how galaxies detected at submillimeter wavelengths are related to ultraviolet/optical-selected galaxies in terms of their observed quantities, physical properties, and evolutionary stages. Deep near- and mid-infrared observational data are crucial to characterize the stellar properties of galaxies detected with submillimeter emission. In this study, we make use of a galaxy catalog from the Spitzer Matching survey of the UltraVISTA ultra-deep Stripes. By crossmatching with a submillimeter source catalog constructed with archival data of the Atacama Large Millimeter/submillimeter Array (ALMA), we search for galaxies at z > 2 with a submillimeter detection in our galaxy catalog. We find that the ALMA-detected galaxies at z > 2 are systematically massive and have redder K s –[4.5] colors than the nondetected galaxies. The redder colors are consistent with the larger dust reddening values of the ALMA-detected galaxies obtained from spectral energy distribution (SED) fitting. We also find that the ALMA-detected galaxies tend to have brighter 4.5 μ m magnitudes. This may suggest that they tend to have smaller mass-to-light ratios and thus to be younger than star-forming galaxies fainter at submillimeter wavelengths with similar stellar masses. We identify starburst galaxies with high specific star formation rates among both ALMA-detected and nondetected SMUVS sources. Irrespective of their brightness at submillimeter wavelengths, these populations have similar dust reddening values, which may suggest a variety of dust SED shapes among the starburst galaxies at z > 2. [ABSTRACT FROM AUTHOR]

Previous surveys in the far-infrared have found very few, if any, M-dwarf debris discs among their samples. It has been questioned whether M-dwarf discs are simply less common than earlier types, or whether the low detection rate derives from the wavelengths and sensitivities available to those studies. The highly sensitive, long-wavelength Atacama Large Millimetre/submillimetre Array (ALMA) can shed light on the problem. This paper presents a survey of M-dwarf stars in the young and nearby Beta Pictoris Moving Group with ALMA at Band 7 (880 μm). From the observational sample, we detect two new sub-mm excesses that likely constitute unresolved debris discs around GJ 2006 A and AT Mic A and model distributions of the disc fractional luminosities and temperatures. From the science sample of 36 M-dwarfs including AU Mic, we find a disc detection rate of 4/36 or 11.1 |$^{+7.4}_{-3.3}$|  per cent that rises to 23.1 |$^{+8.3}_{-5.5}$|  per cent when adjusted for completeness. We conclude that this detection rate is consistent with the detection rate of discs around G- and K-type stars and that the disc properties are also likely consistent with earlier type stars. We additionally conclude that M-dwarf stars are not less likely to host debris discs, but instead their detection requires longer wavelength and higher sensitivity observations than have previously been employed. [ABSTRACT FROM AUTHOR]

Mapping of multiple lines such as the fine-structure emission from [C ii ] (157.7 μ m), [O iii ] (52 and 88.4 μ m), and rotational emission lines from CO are of particular interest for upcoming line intensity mapping (LIM) experiments at millimeter wavelengths, due to their brightness features. Several upcoming experiments aim to cover a broad range of scientific goals, from detecting signatures of the epoch of reionization to the physics of star formation and its role in galaxy evolution. In this paper, we develop a semianalytic approach to modeling line strengths as functions of the star formation rate (SFR) or infrared luminosity based on observations of local and high- z galaxies. This package, LIMpy (Line Intensity Mapping in Python), estimates the intensity and power spectra of [C ii ], [O iii ], and CO rotational transition lines up to the J levels (1–0) to (13–12) based both on analytic formalism and on simulations. We develop a relation among halo mass, SFR, and multiline intensities that permits us to construct a generic formula for the evolution of several line strengths up to z ∼ 10. We implement a variety of star formation models and multiline luminosity relations to estimate the astrophysical uncertainties on the intensity power spectrum of these lines. As a demonstration, we predict the signal-to-noise ratio of [C ii ] detection for an EoR-Spec-like instrument on the Fred Young Submillimeter Telescope. Furthermore, the ability to use any halo catalog allows the LIMpy code to be easily integrated into existing simulation pipelines, providing a flexible tool to study intensity mapping in the context of complex galaxy formation physics. [ABSTRACT FROM AUTHOR]

Radio astronomical observations at millimeter and submillimeter wavelengths are a very important tool for astrophysical research. However, there is a huge area in northeastern Eurasia, including the whole Russian territory, which lacks sufficiently large radio telescopes effectively operating at these wavelengths. In this review, we describe our long-term efforts to find suitable sites for such radio telescopes in this area, that is, sites with good atmospheric transparency at millimeter and submillimeter waves. We describe methods and instruments used for measurements and evaluations of the atmospheric opacity. They include special radiometric systems, which are used for estimations of the atmospheric opacity in the transparency windows from the sky brightness measurements. Evaluation of the precipitable water vapor from such measurements by the artificial neural network is discussed. Other approaches use water vapor radiometers, global atmospheric models and signals of the Global Navigation Satellite Systems. To date, long-term radiometric monitoring has been performed at several candidate sites, and atmospheric conditions for many sites have been evaluated using global atmospheric models. Several sites with the best atmospheric transparency at millimeter and submillimeter wavelengths have been selected. They can be effectively used for astronomical observations, at least in the major atmospheric transparency windows at 1.3 mm and 0.85 mm. In general, the results show that northeastern Eurasia is a promising area for submillimeter astronomy. These results can also be used for space communications and radar systems. [ABSTRACT FROM AUTHOR]

The dust size in protoplanetary disks is a crucial parameter for understanding planet formation, while the observational constraints on dust size distribution have large uncertainties. In this study, we present a new method to constrain the dust size distribution from the dust spatial distribution, utilizing the fact that larger dust grains are more spatially localized. We analyze Atacama Large Millimeter/submillimeter Array Band 6 (1.25 mm) and Band 4 (2.14 mm) high-resolution images and constrain the dust size distribution in the two rings of the HD 163296 disk. We find that the outer ring at 100 au appears narrower at longer wavelengths, while the inner ring at 67 au appears to have similar widths across the two wavelengths. We model dust rings trapped at gas pressure maxima, where the dust grains follow a power-law size distribution, and the dust grains of a specific size follow a Gaussian spatial distribution, with the width depending on the grain size. By comparing the observations with the models, we constrain the maximum dust size a max and the exponent of the dust size distribution p. We constrain 0.9 mm < a max < 5 mm and p < 3.3 in the inner ring, and a max > 3 × 10 1 mm and 3.4 < p < 3.7 in the outer ring. The larger maximum dust size in the outer ring implies a spatial dependency in dust growth, potentially influencing the formation location of the planetesimals. We further discuss the turbulence strength α derived from the constrained dust spatial distribution, assuming equilibrium between turbulent diffusion and the accumulation of dust grains. [ABSTRACT FROM AUTHOR]

Context. The Fred Young Submillimeter Telescope (FYST) and the Simons Observatory Large Aperture Telescope (SO LAT) will deliver unprecedented high-resolution measurements of microwave sky emissions. Notably, one of those microwave sky emissions, the thermal Sunyaev–Zeldovich (tSZ) signal, is an essential probe for cluster astrophysics and cosmology. However, an obstacle to its measurement is contamination by the cosmic infrared background (CIB), especially at high frequencies. Aims. Our goal is to assess the detection and purity of tSZ power spectrum measurements from these two telescopes. We demonstrate that FYST's high-frequency coverage helps lower CIB contamination and improves signal detection. Methods. We simulated the various components of the microwave sky at the frequencies, sensitivities, and beam sizes of the upcoming SO LAT and FYST telescopes using full-sky Hierarchical Equal Area isoLatitude Pixelisation (HEALPix) map templates from the Websky simulations and the Python Sky Model (PySM). We used a map-based internal linear combination (ILC) and a constrained ILC (CILC) to extract the tSZ signal and compute residual noises to assess CIB contamination and signal recovery. Results. We find that the CIB's residual noise power spectrum in the ILC-recovered tSZ is lowered by ∼35% on average over the scales ℓ ∈ [500, 5000] when SO LAT and FYST are combined compared to when SO LAT is used alone. We find that when using CILC to deproject CIB, the combined abilities of SO LAT and FYST offer a large ℓ ∈ [1800, 3500] window in which the recovered tSZ power spectrum is not noise dominated. [ABSTRACT FROM AUTHOR]

We use the latest results from Atacama Large Millimetre/submillimetre Array (ALMA) surveys targeting the ionized carbon [C  ii ] 158  μ m and oxygen [O  iii ] 88  μ m lines, in combination with data-driven predictions for the evolution of neutral hydrogen (H  i), to illustrate the prospects for intensity mapping cross-correlations between 21 cm and submillimetre surveys over z ∼ 5 – 7. We work with a data set including the ALPINE and REBELS surveys for [C  ii ] over z ∼ 4.5 – 7, and ALMA [O  iii ] detections over z ∼ 6 – 9. The resultant evolution of the [C  ii ] luminosity–halo mass relation is well described by a double power law at high redshifts, with the best-fitting parameters in good agreement with the results of simulations. The data favour secure detections of the autopower spectrum of [C  ii ] at all redshifts with an enhanced Fred Young Submillimetre Telescope (FYST)-like configuration. Such an experiment, along with the Murchison Widefield Array (MWA) will be able to measure the 21 cm - [C  ii ] cross-correlation power with a signal-to-noise ratio of a few tens to a few hundreds. We find that a balloon-borne experiment improving upon the Experiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) should be able to detect the 21 cm - [O  iii ] cross-correlation with the MWA and the Square Kilometre Array (SKA)-LOW out to z ∼ 7. Our results have implications for constraining the evolution of luminous sources during the mid-to-end stages of reionization. [ABSTRACT FROM AUTHOR]

Star formation is a complex process that typically occurs in dense regions of molecular clouds mainly regulated by magnetic fields, magnetohydrodynamic (MHD) turbulence, and self-gravity. However, it remains a challenging endeavour to trace the magnetic field and determine regions of gravitational collapse, where the star is forming. Based on the anisotropic properties of MHD turbulence, a new technique termed velocity gradient technique (VGT) has been proposed to address these challenges. In this study, we apply the VGT to two regions of the giant California Molecular Cloud (CMC), namely, L1478 and L1482, and analyse the difference in their physical properties. We use the 12CO (J = 2–1), 13CO (J = 2–1), and C18O (J = 2–1) emission lines observed with the Heinrich Hertz Submillimeter Telescope. We compare VGT results calculated in the resolutions of 3.3 and 10 arcmin to Planck polarization at 353 GHz and 10 arcmin to determine areas of MHD turbulence dominance and self-gravity dominance. We show that the resolution difference can introduce misalignment between the two measurements. We find the VGT-measured magnetic fields globally agree with those from Planck in L1478, suggesting self-gravity's effect is insignificant. The best agreement appears in VGT-12CO. As for L1482, the VGT measurements are statistically perpendicular to the Planck polarization indicating the dominance of self-gravity. This perpendicular alignment is more significant in VGT-13CO and VGT-C18O. [ABSTRACT FROM AUTHOR]

Finding high-redshift (z ≫ 4) dusty star-forming galaxies is extremely challenging. It has recently been suggested that millimeter selections may be the best approach since the negative K-correction makes galaxies at a given far-infrared luminosity brighter at z ≳ 4 than those at z = 2–3. Here we analyze this issue using a deep Atacama Large Millimeter/submillimeter Array (ALMA) 2 mm sample obtained by targeting ALMA 870 μ m priors (these priors were the result of targeting SCUBA-2 850 μ m sources) in the GOODS-S. We construct prior-based 2 mm galaxy number counts and compare them with published blank field-based 2 mm counts, finding good agreement down to 0.2 mJy. Only a fraction of the current 2 mm extragalactic background light is resolved, and we estimate what observational depths may be needed to resolve it fully. By complementing the 2 mm ALMA data with a deep SCUBA-2 450 μ m sample, we exploit the steep gradient with a redshift of the 2 mm–450 μ m flux density ratio to estimate redshifts for those galaxies without spectroscopic or robust optical/near-infrared photometric redshifts. Our observations measure galaxies with star formation rates in excess of 250 M ⊙ yr−1. For these galaxies, the star formation rate densities fall by a factor of 9 from z = 2–3 to z = 5–6. [ABSTRACT FROM AUTHOR]

The Atacama Large Millimetre/submillimetre Array (ALMA) is the world's most advanced radio interferometric facility, producing science data with an average rate of about 1 TB per day. After a process of calibration, imaging and quality assurance, the scientific data are stored in the ALMA Science Archive (ASA), along with the corresponding raw data, making the ASA an invaluable resource for original astronomical research. Due to their complexity, each ALMA data set has the potential for scientific results that go well beyond the ideas behind the original proposal that led to each observation. For this reason, the European ALMA Regional Centre initiated the High-Level Data Products initiative to develop science-oriented data products derived from data sets publicly available in the ASA, that go beyond the formal ALMA deliverables. The first instance of this initiative is the creation of a catalogue of submillimetre (submm) detections of Sloan Digital Sky Survey (SDSS) quasars from the SDSS Data Release 14 that lie in the aggregate ALMA footprint observed since ALMA Cycle 0. The ALMA fluxes are extracted in an automatic fashion, using the ALMA Data Mining Toolkit. All extractions above a signal-to-noise cut of 3.5 are considered, they have been visually inspected and the reliable detections are presented in a catalogue of 376 entries, corresponding to 275 unique quasars. Interesting targets found in the process, i.e. lensed or jetted quasars as well as quasars with nearby submm counterparts are highlighted, to facilitate further studies or potential follow up observations. [ABSTRACT FROM AUTHOR]

While dust disks around optically visible, Class II protostars are found to be vertically thin, when and how dust settles to the midplane are unclear. As part of the Atacama Large Millimeter/submillimeter Array large program, Early Planet Formation in Embedded Disks, we analyze the edge-on, embedded, Class I protostar IRAS 04302+2247, also nicknamed the "Butterfly Star." With a resolution of 0.″05 (8 au), the 1.3 mm continuum shows an asymmetry along the minor axis that is evidence of an optically thick and geometrically thick disk viewed nearly edge-on. There is no evidence of rings and gaps, which could be due to the lack of radial substructure or the highly inclined and optically thick view. With 0.″1 (16 au) resolution, we resolve the 2D snow surfaces, i.e., the boundary region between freeze-out and sublimation, for 12CO J = 2–1, 13CO J = 2–1, C18O J = 2–1, H 2CO J = 30,3–20,2, and SO J = 65–54, and constrain the CO midplane snow line to ∼130 au. We find Keplerian rotation around a protostar of 1.6 ± 0.4 M ⊙ using C18O. Through forward ray-tracing using RADMC-3D, we find that the dust scale height is ∼6 au at a radius of 100 au from the central star and is comparable to the gas pressure scale height. The results suggest that the dust of this Class I source has yet to vertically settle significantly. [ABSTRACT FROM AUTHOR]

We present an overview of the Large Program, "Early Planet Formation in Embedded Disks (eDisk)," conducted with the Atacama Large Millimeter/submillimeter Array (ALMA). The ubiquitous detections of substructures, particularly rings and gaps, in protoplanetary disks around T Tauri stars raise the possibility that at least some planet formation may have already started during the embedded stages of star formation. In order to address exactly how and when planet formation is initiated, the program focuses on searching for substructures in disks around 12 Class 0 and 7 Class I protostars in nearby (<200 pc) star-forming regions through 1.3 mm continuum observations at a resolution of ∼7 au (0.″04). The initial results show that the continuum emission, mostly arising from dust disks around the sample protostars, has relatively few distinctive substructures, such as rings and spirals, in marked contrast to Class II disks. The dramatic difference may suggest that substructures quickly develop in disks when the systems evolve from protostars to Class II sources, or alternatively that high optical depth of the continuum emission could obscure internal structures. Kinematic information obtained through CO isotopologue lines and other lines reveals the presence of Keplerian disks around protostars, providing us with crucial physical parameters, in particular, the dynamical mass of the central protostars. We describe the background of the eDisk program, the sample selection and their ALMA observations, and the data reduction, and we also highlight representative first-look results. [ABSTRACT FROM AUTHOR]

High-energy processes are ubiquitous even in the earliest stages of protostellar evolution. Motivated by the results of our systematic search for intense centimetre radio flares in Young Stellar Objects (YSOs) and by rare findings of strong millimetre-wavelength variability, we have conducted a systematic search for such variability in the Orion Nebula Cluster (ONC) using Atacama Large Millimetre/submillimetre Array (ALMA). Rapid variability on time-scales of minutes to hours in the (centimetre) millimetre-wavelength range indicates (gyro)synchrotron radiation. Additionally, mass accretion will also affect the millimetre-wavelength luminosity but typically on longer time-scales. Beyond studies of individual YSOs, our characterization of strong millimetre-wavelength variability with ALMA in the ONC sets first systematic constraints on the occurrence of such variability in a large number of YSOs (∼130). We report the discovery of an order of magnitude millimetre-flare within just a few minutes from a known YSO previously reported as a radio flaring source at cm-wavelengths (the 'ORBS' source). We also present an assessment of the systematic variability effects caused by the use of time-sliced imaging of a complex region. These are mostly due to the impact of a changing synthesized beam throughout the observations. We use simulated ALMA observations to reproduce and quantify these effects, and set a lower limit for the variability that can be studied using our method in a complex region such as the ONC. Our results demonstrate that the utility of time domain analysis of YSOs extends into the millimetre-wavelength range, potentially interfering with the conversion of observed fluxes into dust masses. [ABSTRACT FROM AUTHOR]

The discovery of abundant carbon-chain molecules in protostellar cores motivates the development of the warm carbon-chain chemistry. To understand the role of warm carbon-chain chemistry in star-forming regions, we studied C2H and c-C3H2 in 15 embedded protostars in the Taurus molecular cloud, whose evolutionary stages range from prestellar to Class I/II, using data from the Submillimeter Telescope (SMT). We calculated the excitation temperature, column density, and abundance of C2H and c-C3H2 in each source. We compared those properties with evolutionary indicators of the protostars. We also estimated the kinetic temperature using RADEX. Finally, we compared the abundance of C2H and c-C3H2 in our survey with that in the survey of protostellar cores in the Perseus molecular cloud. While we are unable to identify new WCCCs, our results suggest that the abundances of C2H and c-C3H2 could be an indicator to find WCCC candidates. [ABSTRACT FROM AUTHOR]

We report the results of Atacama Large Millimeter/submillimeter Array (ALMA) 1–2 kpc resolution, three rotational transition-line (J = 2–1, J = 3–2, and J = 4–3) observations of multiple dense molecular gas tracers (HCN, HCO+, and HNC) for 10 nearby (ultra)luminous infrared galaxies ((U)LIRGs). Following the matching of beam sizes to 1–2 kpc for each (U)LIRG, the high- J -to-low- J transition-line flux ratios of each molecule and the emission-line flux ratios of different molecules at each J transition are derived. We conduct RADEX non-LTE model calculations and find that, under a wide range of gas density and kinetic temperature, the observed HCN-to-HCO+ flux ratios in the overall (U)LIRGs are naturally reproduced with enhanced HCN abundance compared to HCO+. Thereafter, molecular gas properties are constrained primarily through the use of HCN and HCO+ data and the adoption of fiducial values for the HCO+ column density and HCN-to-HCO+ abundance ratio. We quantitatively confirm the following: (i) molecular gas at the (U)LIRGs' nuclei is dense (≳103–4 cm−3) and warm (≳100 K), (ii) the molecular gas density and temperature in nine ULIRGs' nuclei are significantly higher than those of one LIRG's nucleus, (iii) molecular gas in starburst-dominated sources tends to be less dense and cooler than ULIRGs with luminous AGN signatures. For six selected sources, we also apply a Bayesian approach by freeing all parameters and support the above main results. Our ALMA 1–2 kpc resolution, multiple transition-line data of multiple molecules are a very powerful tool for scrutinizing the properties of molecular gas concentrated around luminous energy sources in nearby (U)LIRGs' nuclei. [ABSTRACT FROM AUTHOR]

We report the observation by the Atacama Large Millimeter/submillimeter Array (ALMA) of a z ≳ 10 galaxy candidate (GHZ1) discovered from the GLASS–JWST Early Release Science Program. Our ALMA program aims to detect the [O iii ] emission line at the rest-frame frequency 3393.0062 GHz (88.36 μ m) and far-IR continuum emission with the spectral window setup seamlessly covering a 26.125 GHz frequency range (10.10 < z < 11.14). A total of 7 hr of on-source integration was employed, using four frequency settings to cover the full range (1.7 hr per setting), with 0.″7 angular resolution. No line or continuum is clearly detected, with 5 σ upper limits on the line emission of 0.93 mJy beam−1 at 25 km s−1 channel−1 and on the continuum emission of 30 μ Jy beam−1. We report marginal spectral (at 225 km s−1 resolution) and continuum features (4.1 σ and 2.6 σ peak signal-to-noise ratio, respectively), within 0.″17 from the JWST position of GHZ1. This spectral feature implies z = 10.38 and needs to be verified with further observations. Assuming that the best estimate of photometric redshift ( z = 10.60 − 0.60 + 0.52 ) is correct, the model of the galaxy's broadband spectral energy distribution for the 3 σ upper limit of the continuum flux from GHZ1 suggests that GHZ1 has a small amount of dust (M d ≲ 104 M ⊙) at a high temperature (T d ≳ 90 K). The 5 σ upper limit on the [O iii ]88 μ m line luminosity and the inferred star formation rate of GHZ1 are consistent with the properties of low-metallicity dwarf galaxies. We also report serendipitous clear detections of six continuum sources at the locations of the JWST galaxy counterparts in the field. [ABSTRACT FROM AUTHOR]

We present new NOrthern Extended Millimeter Array (NOEMA) observations of the CO(2–1) emission in eight of the brightest Palomar-Green quasars at z ≲ 0.5 to investigate the role of active galactic nucleus (AGN) feedback in luminous quasars detected at low redshifts. We detect CO(2–1) emission in three objects, from which we derive CO luminosities, molecular gas masses and fractions, and gas depletion times. In combination with data available in the literature, we build a total sample of 138 local type 1 AGNs with CO(2–1) measurements. We compare the AGN properties with the host galaxy molecular gas properties, considering systems nondetected in CO emission. We find that the CO luminosity does not correlate with AGN luminosity and Eddington ratio, while the molecular gas fraction is weakly correlated with Eddington ratio. The type 1 AGNs can be roughly separated into two populations in terms of infrared-to-CO luminosity ratio, with one population presenting values typically found in normal star-forming systems, while the other having lower ratio values, comparable to those measured for starbursts. We find no evidence that AGN feedback rapidly quenches star formation in type 1 AGNs. Our results may imply an underlying the role of host galaxy gravitational instabilities or the fast inflow of cold gas in triggering AGN activity. [ABSTRACT FROM AUTHOR]

We report the results of observations toward the center of the molecular cloud CO 0.02–0.02 made using the Atacama Large Millimeter/Submillimeter Array. The successfully obtained 1″ resolution images of CO J = 3–2, H13CN J = 4–3, H13CO+ J = 4–3, SiO J = 8–7, CH3OH J K a , K c = 71,7–61,6 A+ lines, and 900 μ m continuum show several new features, which have not been identified in previous observations. The dense gas probe (H13CN, SiO, CH3OH) images are dominated by a pair of northeast-southwest elongated filaments, which may be the main body of CO 0.02–0.02. Two striped patterns perpendicular to each other (F1 and F2) and a high-velocity feature (HV), which appear in different velocity ranges, were prominent in the CO image. An emission hole that may represent an expanding feature was found in the F1 velocity range. F2 appeared to align along the western edge of a 20 pc × 13 pc ellipse (the Large Shell) identified in the single-dish CO map. The HV contains eight compact clumps at the positive high-velocity end of the CO emissions. Based on these results, we propose a formation scenario for CO 0.02–0.02; internal explosions of supernovae, external perturbations by the Large Shell, and gravitational acceleration by a less-luminous star cluster have formed CO 0.02–0.02 in its current state. [ABSTRACT FROM AUTHOR]

ϵ Eridani is the closest star to our Sun known to host a debris disc. Prior observations in the (sub-)millimetre regime have potentially detected clumpy structure in the disc and attributed this to interactions with an (as yet) undetected planet. However, the prior observations were unable to distinguish between structure in the disc and background confusion. Here, we present the first ALMA image of the entire disc, which has a resolution of 1.6 × 1.2 arcsec2. We clearly detect the star, the main belt, and two-point sources. The resolution and sensitivity of this data allow us to clearly distinguish background galaxies (that show up as point sources) from the disc emission. We show that the two-point sources are consistent with background galaxies. After taking account of these, we find that resolved residuals are still present in the main belt, including two clumps with a >3σ significance – one to the east of the star and the other to the north-west. We perform N -body simulations to demonstrate that a migrating planet can form structures similar to those observed by trapping planetesimals in resonances. We find that the observed features can be reproduced by a migrating planet trapping planetesimals in the 2:1 mean motion resonance and the symmetry of the most prominent clumps means that the planet should have a position angle of either ∼10° or ∼190°. Observations over multiple epochs are necessary to test whether the observed features rotate around the star. [ABSTRACT FROM AUTHOR]

Observations across the electromagnetic spectrum of radiative processes involving interstellar dust—emission, absorption, and scattering—are used to constrain the parameters of dust models and more directly to aid in foreground removal of dust for extragalactic and cosmological observations. Dust models can benefit from more independent constraints from complementary observations. Here, we quantify the relationship between scattered light and thermal emission from dust in a diffuse (cirrus) intermediate-latitude cloud, Spider, using data from the Dragonfly Telephoto Array and the Herschel Space Observatory. A challenge for optical observations of faint diffuse cirrus is accurate removal of a contaminating, spatially varying sky. We present a technique to analyze two images of the same cirrus field concurrently, correlating pixel values to capture the relationship and simultaneously fitting the sky-related signal as a complex noncorrelating additive component. For the Spider, we measure a color g − r = 0.644 ± 0.024 and ratios of visible-wavelength to 250 μ m intensity of γ g,250 = (0.855 ± 0.025) × 10−3 and γ r,250 = (1.55 ± 0.08) × 10−3 for the g and r- bands, respectively. We show how to use any dust model that matches the thermal dust emission to predict an upper limit to the amount of scattered light. The actual brightness of the cirrus will be fainter than this limit because of anisotropic scattering by the dust combined with anisotropy of the incident interstellar radiation field (ISRF). Using models of dust and the ISRF in the literature, we illustrate that the predicted brightness is indeed lower, though not as faint as the observations indicate. [ABSTRACT FROM AUTHOR]

We present a demographic analysis of the physical and morphological properties of |$450/850~\mu \rm m$| -selected galaxies from the deep observations of the SCUBA-2 Cosmology Legacy Survey in the Extended Groth Strip that are detected below the classical submillimetre-galaxy regime (⁠|$S_{850\, \mu \rm m}\lesssim 6~\rm mJy$|  beam−1) and compare them with a sample of optically selected star-forming galaxies detected in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey in the same field. We derive the evolution of the main sequence of star-forming galaxies, finding a steeper specific star formation rate versus stellar mass at z > 2.5 than previous studies. Most faint submillimetre-galaxies fall within 3σ of the main sequence, but 40 per cent are classified as starbursts. Faint submillimetre galaxies have 50 per cent larger sizes at 2 < z < 3 than optically selected star-forming galaxies of the same mass range. This is also the redshift bin where we find the largest fraction of starbursts, and hence we could be witnessing merging processes, as confirmed by the preference for visual-morphology classifications of these systems as irregular disc galaxies and mergers. Both populations show an increment towards lower redshifts (z < 2) of their concentration in H -band morphology, but faint submillimetre galaxies on average show larger concentration values at later times. These findings support the claim that faint submillimetre galaxies are mostly a population of massive dust-obscured disc-like galaxies that develop larger bulge components at later epochs. While the similarities are great, the median sizes, starburst numbers, and H -band concentration of faint submillimetre galaxies differ from those of optically selected star-forming galaxies of the same stellar mass. [ABSTRACT FROM AUTHOR]