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1811. SSDF survey: IRAC catalogs
ID:
ivo://CDS.VizieR/J/ApJS/209/22
Title:
SSDF survey: IRAC catalogs
Short Name:
J/ApJS/209/22
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Spitzer South Pole Telescope Deep Field (SSDF) is a wide-area survey using Spitzer's Infrared Array Camera (IRAC) to cover 94deg^2^ of extragalactic sky, making it the largest IRAC survey completed to date outside the Milky Way midplane. The SSDF is centered at ({alpha},{delta})=(23:30, -55:00), in a region that combines observations spanning a broad wavelength range from numerous facilities. These include millimeter imaging from the South Pole Telescope (SPT), far-infrared observations from Herschel/SPIRE, X-ray observations from the XMM XXL survey, near-infrared observations from the VISTA Hemisphere Survey, and radio-wavelength imaging from the Australia Telescope Compact Array, in a panchromatic project designed to address major outstanding questions surrounding galaxy clusters and the baryon budget. Here we describe the Spitzer/IRAC observations of the SSDF, including the survey design, observations, processing, source extraction, and publicly available data products. In particular, we present two band-merged catalogs, one for each of the two warm IRAC selection bands. They contain roughly 5.5 and 3.7 million distinct sources, the vast majority of which are galaxies, down to the SSDF 5{sigma} sensitivity limits of 19.0 and 18.2 Vega mag (7.0 and 9.4uJy) at 3.6 and 4.5um, respectively.
1812. STAGES master catalog
ID:
ivo://CDS.VizieR/J/MNRAS/393/1275
Title:
STAGES master catalog
Short Name:
J/MNRAS/393/1275
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an overview of the Space Telescope A901/2 Galaxy Evolution Survey (STAGES). STAGES is a multiwavelength project designed to probe physical drivers of galaxy evolution across a wide range of environments and luminosity. A complex multicluster system at z~0.165 has been the subject of an 80-orbit F606W Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) mosaic covering the full 0.5x0.5deg^2^ (~5x5Mpc^2^) span of the supercluster. Extensive multiwavelength observations with XMM-Newton, GALEX, Spitzer, 2dF, Giant Metrewave Radio Telescope and the 17-band COMBO-17 photometric redshift survey complement the HST imaging. Our survey goals include simultaneously linking galaxy morphology with other observables such as age, star formation rate, nuclear activity and stellar mass. In addition, with the multiwavelength data set and new high-resolution mass maps from gravitational lensing, we are able to disentangle the large-scale structure of the system. By examining all aspects of an environment we will be able to evaluate the relative importance of the dark matter haloes, the local galaxy density and the hot X-ray gas in driving galaxy transformation.
1813. Star clusters automatically detected in the LMC
ID:
ivo://CDS.VizieR/J/ApJ/845/56
Title:
Star clusters automatically detected in the LMC
Short Name:
J/ApJ/845/56
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present our new, fully automated method to detect and measure the ages of star clusters in nearby galaxies, where individual stars can be resolved. The method relies purely on statistical analysis of observations and Monte-Carlo simulations to define stellar overdensities in the data. It decontaminates the cluster color-magnitude diagrams and, using a revised version of the Bayesian isochrone fitting code of Ramirez-Siordia+ (2017, in prep.), estimates the ages of the clusters. Comparisons of our estimates with those from other surveys show the superiority of our method to extract and measure the ages of star clusters, even in the most crowded fields. An application of our method is shown for the high-resolution, multiband imaging of the Large Magellanic Cloud. We detect 4850 clusters in the 7deg^2^ we surveyed, 3451 of which have not been reported before. Our findings suggest multiple epochs of star cluster formation, with the most probable occurring ~310Myr ago. Several of these events are consistent with the epochs of the interactions among the Large and Small Magellanic Clouds, and the Galaxy, as predicted by N-body numerical simulations. Finally, the spatially resolved star cluster formation history may suggest an inside-out cluster formation scenario throughout the LMC, for the past 1Gyr.
1814. Star formation activities in MaNGA low-mass galaxies
ID:
ivo://CDS.VizieR/J/ApJ/894/57
Title:
Star formation activities in MaNGA low-mass galaxies
Short Name:
J/ApJ/894/57
Date:
03 Dec 2021 00:39:35
Publisher:
CDS
Description:
We explore the environmental influences on the star formation (SF) in low-mass galaxies with stellar mass 8<=log(M_*_/M_{sun}_)<=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 M_Neighbor_/M_Candidate_<=4 at a projected separation within d_proj_<=1500kpc and a line-of-sight kinematic separation of {Delta}v_LOS_<=300km/s. Our control galaxies are isolated from other galaxies within a projected radius of 1500kpc. 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/R_e_<=0.5 (inner), 0.5<=R/R_e_<=1.0 (middle), and 1.0<=R/R_e_<=1.5 (outer), in which R_e_ 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 {Delta}v_LOS_<=100km/s at d_proj_<=400kpc. We use stellar-mass-weighted SF rate surface density ({Sigma}SFR/M_*_) to describe the SF strength in each radially binned region. For the pair candidates with 0.25<=M_Neighbor_/M_Candidate_<=4 at d_proj_<=100kpc and {Delta}v_LOS_<=100km/s, we observe an SF enhancement of f_{Delta}SF_=1.75+/-0.96 (f_{Delta}SF_=[({Sigma}SFR/M_*_)_Pair_-({Sigma}SFR/M_*_)_Control,mean_] /({Sigma}SFR/M_*_)_Control,mean_) in their inner regions, which decreases with increasing galactic radii.
1815. Star formation in E/S0 galaxies
ID:
ivo://CDS.VizieR/J/ApJ/708/841
Title:
Star formation in E/S0 galaxies
Short Name:
J/ApJ/708/841
Date:
21 Oct 2021
Publisher:
CDS
Description:
Recent work has identified a population of low-redshift E/S0 galaxies that lie on the blue sequence in color versus stellar mass parameter space, where spiral galaxies typically reside. While high-mass blue-sequence E/S0s often resemble young merger or interaction remnants likely to fade to the red sequence, we focus on blue-sequence E/S0s with lower stellar masses (M_*_<a fewx10^10^M_{sun}_), which are characterized by fairly regular morphologies and low-density field environments where fresh gas infall is possible. This population may provide an evolutionary link between early-type galaxies and spirals through disk regrowth. Focusing on atomic gas reservoirs, we present new GBT HI data for 27 E/S0s on both sequences as well as a complete tabulation of archival HI data for other galaxies in the Nearby Field Galaxy Survey. Normalized to stellar mass, the atomic gas masses for 12 of the 14 blue-sequence E/S0s range from 0.1 to >1.0, demonstrating that morphological transformation is possible if the detected gas can be converted into stars. These gas-to-stellar mass ratios are comparable to those of spiral and irregular galaxies and have a similar dependence on stellar mass.
1816. Star Formation in Radio Survey (SFRS): 33GHz obs.
ID:
ivo://CDS.VizieR/J/ApJ/761/97
Title:
Star Formation in Radio Survey (SFRS): 33GHz obs.
Short Name:
J/ApJ/761/97
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 33GHz photometry of 103 galaxy nuclei and extranuclear star-forming complexes taken with the Green Bank Telescope (GBT) as part of the Star Formation in Radio Survey (SFRS). Among the sources without evidence for an active galactic nucleus, and also having lower frequency radio data, we find a median thermal fraction at 33GHz of {approx}76% with a dispersion of {approx}24%. For all sources resolved on scales <~0.5kpc, the thermal fraction is even larger, being >~90%. This suggests that the rest-frame 33GHz emission provides a sensitive measure of the ionizing photon rate from young star-forming regions, thus making it a robust star formation rate (SFR) indicator. Taking the 33 GHz SFRs as a reference, we investigate other empirical calibrations relying on different combinations of warm 24{mu}m dust, total infrared (IR; 8-1000{mu}m), H{alpha} line, and far-UV continuum emission. The recipes derived here generally agree with others found in the literature, albeit with a large dispersion that most likely stems from a combination of effects. Comparing the 33GHz to total IR flux ratios as a function of the radio spectral index, measured between 1.7 and 33GHz, we find that the ratio increases as the radio spectral index flattens which does not appear to be a distance effect. Consequently, the ratio of non-thermal to total IR emission appears relatively constant, suggesting only moderate variations in the cosmic-ray electron injection spectrum and ratio of synchrotron to total cooling processes among star-forming complexes. Assuming that this trend solely arises from an increase in the thermal fraction sets a maximum on the scatter of the non-thermal spectral indices among the star-forming regions of {sigma}_{alpha}_NT<~0.13.
1817. Star Formation Reference Survey (SFRS)
ID:
ivo://CDS.VizieR/J/PASP/123/1011
Title:
Star Formation Reference Survey (SFRS)
Short Name:
J/PASP/123/1011
Date:
21 Oct 2021
Publisher:
CDS
Description:
Star formation is arguably the most important physical process in the cosmos. It is a fundamental driver of galaxy evolution and the ultimate source of most of the energy emitted by galaxies. A correct interpretation of star formation rate (SFR) measures is therefore essential to our understanding of galaxy formation and evolution. Unfortunately, however, no single SFR estimator is universally available or even applicable in all circumstances: the numerous galaxies found in deep surveys are often too faint (or too distant) to yield significant detections with most standard SFR measures, and until now there have been no global, multi-band observations of nearby galaxies that span all the conditions under which star-formation is taking place. To address this need in a systematic way, we have undertaken a multi-band survey of all types of star-forming galaxies in the local Universe. This project, the Star Formation Reference Survey (SFRS), is based on a statistically valid sample of 369 nearby galaxies that span all existing combinations of dust temperature, SFR, and specific SFR. Furthermore, because the SFRS is blind with respect to AGN fraction and environment it serves as a means to assess the influence of these factors on SFR. Our panchromatic global flux measurements (including GALEX FUV+NUV, SDSS ugriz, 2MASS JHKs, Spitzer 3-8um, and others) furnish uniform SFR measures and the context in which their reliability can be assessed. This paper describes the SFRS survey strategy, defines the sample, and presents the multi-band photometry collected to date.
1818. Star-forming clumps in local luminous IR galaxies
ID:
ivo://CDS.VizieR/J/ApJ/888/92
Title:
Star-forming clumps in local luminous IR galaxies
Short Name:
J/ApJ/888/92
Date:
25 Oct 2021 10:18:57
Publisher:
CDS
Description:
We present HST narrowband near-infrared imaging of Pa{alpha} and Pa{beta} emission of 48 local luminous infrared galaxies (LIRGs) from the Great Observatories All-Sky LIRG Survey. These data allow us to measure the properties of 810 spatially resolved star-forming regions (59 nuclei and 751 extranuclear clumps) and directly compare their properties to those found in both local and high-redshift star-forming galaxies. We find that in LIRGs the star-forming clumps have radii ranging from ~90 to 900pc and star formation rates (SFRs) of ~1x10^-3^ to 10M_{sun}_/yr, with median values for extranuclear clumps of 170pc and 0.03M_{sun}_/yr. The detected star-forming clumps are young, with a median stellar age of 8.7Myr, and have a median stellar mass of 5x10^5^M_{sun}_. The SFRs span the range of those found in normal local star-forming galaxies to those found in high-redshift star-forming galaxies at z=1-3. The luminosity function of the LIRG clumps has a flatter slope than found in lower-luminosity, star-forming galaxies, indicating a relative excess of luminous star-forming clumps. In order to predict the possible range of star-forming histories and gas fractions, we compare the star-forming clumps to those measured in the MassiveFIRE high-resolution cosmological simulation. The star-forming clumps in MassiveFIRE cover the same range of SFRs and sizes found in the local LIRGs and have total gas fractions that extend from 10% to 90%. If local LIRGs are similar to these simulated galaxies, we expect that future observations with ALMA will find a large range of gas fractions, and corresponding star formation efficiencies, among the star-forming clumps in LIRGs.
1819. Star-forming galaxies in AKARI Deep Field-South
ID:
ivo://CDS.VizieR/J/A+A/562/A15
Title:
Star-forming galaxies in AKARI Deep Field-South
Short Name:
J/A+A/562/A15
Date:
21 Oct 2021
Publisher:
CDS
Description:
The main aim of this work is the characterization of physical properties of galaxies detected in the far infrared (FIR) in the AKARI Deep Field-South (ADF-S) survey. Starting from a catalog of the brightest 1000 ADF-S sources in the WIDE-S (90um) AKARI band, we constructed a subsample of galaxies with spectral coverage from the ultraviolet to the far-infrared. Then, we analyzed the multiwavelength properties of this 90um-selected sample of galaxies. For galaxies without known spectroscopic redshifts we computed photometric redshifts using codes Le PHARE and CIGALE, tested these photometric redshifts using spectroscopic redshifts, and compared the performances of both codes. To test the reliability of parameters obtained by fitting Spectral Energy Distributions, a mock catalogue has been generated. We built a large multiwavelength catalog of more than 500 ADF-S galaxies. We successfully fitted Spectral Energy Distributions of 186 galaxies with {chi}^2^<4, and analyzed the output parameters of the fits. We conclude that our sample consists mostly of nearby actively star-forming galaxies, and all our galaxies have a relatively high metallicity. We estimated photometric redshifts for 113 galaxies from the whole ADF-S sample. Comparing the performance of Le PHARE and CIGALE, we found that CIGALE gives more reliable redshift estimates for our galaxies, which implies that including the IR photometry allows for substantial improvement of photometric redshift estimation.
1820. Star-forming low-mass gal. stellar host
ID:
ivo://CDS.VizieR/J/A+A/632/A15
Title:
Star-forming low-mass gal. stellar host
Short Name:
J/A+A/632/A15
Date:
21 Oct 2021
Publisher:
CDS
Description:
The morphological evolution of star-forming galaxies provides important clues to understand their physical properties, as well as the triggering and quenching mechanisms of star formation. We analyze the morphology of galaxies hosting star-forming events at low redshift (z<0.36). We aim at connecting morphology and star-formation properties of low-mass galaxies (median stellar mass ~10^8.5^M_{sun}_) beyond the local Universe. We use a sample of medium-band selected star-forming galaxies from the GOODS-North field. H images for the sample are created combining both spectral energy distribution fits and HST data. Using them, we mask the star forming regions to obtain an unbiased two-dimensional model of the light distribution of the host galaxies. For this purpose we use PHI, a new Bayesian photometric decomposition code. We applied it independently to 7 HST bands, from the ultraviolet to the near-infrared, assuming a Sersic surface brightness model. Star-forming galaxy hosts show low Sersic index (with median n~0.9), as well as small sizes (median Re~1.6kpc), and negligible change of the parameters with wavelength (except for the axis ratio, which grows with wavelength in 46% of the sample). Using a clustering algorithm, we find two different classes of star-forming galaxies: A more compact, redder, and high-n (class A) and a more extended, bluer and lower-n one (class B). This separation holds across all seven bands analyzed. In addition, we find evidence that the first class is more spheroidal-like (according to the distribution of observed axis ratios). We compute the color gradients of the host galaxies finding that 48% of the objects where the analysis could be performed show negative gradients, and only in 5% they are positive. The host component of low-mass star-forming galaxies at z<0.36 separates into two different classes, similar to what has been found for their higher mass counterparts. The results are consistent with an evolution from class B to class A. Several mechanisms from the literature, like minor and major mergers, and violent disk instability, can explain the physical process behind the likely transition between the classes.

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