- ID:
- ivo://CDS.VizieR/J/ApJ/691/705
- Title:
- AGN host galaxy morphologies in COSMOS
- Short Name:
- J/ApJ/691/705
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Hubble Space Telescope/Advanced Camera for Surveys images and a photometric catalog of the Cosmic Evolution Survey (COSMOS) field to analyze morphologies of the host galaxies of ~400 active galactic nucleus (AGN) candidates at redshifts 0.3<z<1.0. We compare the AGN hosts with a sample of nonactive galaxies drawn from the COSMOS field to match the magnitude and redshift distribution of the AGN hosts. We perform two-dimensional surface brightness modeling with GALFIT to yield host galaxy and nuclear point source magnitudes. X-ray-selected AGN host galaxy morphologies span a substantial range that peaks between those of early-type, bulge-dominated and late-type, disk-dominated systems. We also measure the asymmetry and concentration of the host galaxies. Unaccounted for, the nuclear point source can significantly bias results of these measured structural parameters, so we subtract the best-fit point source component to obtain images of the underlying host galaxies. Our concentration measurements reinforce the findings of our two-dimensional morphology fits, placing X-ray AGN hosts between early- and late-type inactive galaxies. AGN host asymmetry distributions are consistent with those of control galaxies.
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- ID:
- ivo://CDS.VizieR/J/ApJ/861/49
- Title:
- ALFALFA extragalactic HI source catalog
- Short Name:
- J/ApJ/861/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the catalog of ~31500 extragalactic HI line sources detected by the completed Arecibo Legacy Fast ALFA (ALFALFA) survey out to z<0.06, including both high signal-to-noise ratio (>6.5) detections and ones of lower quality that coincide in both position and recessional velocity with galaxies of known redshift. We review the observing technique, data reduction pipeline, and catalog construction process, focusing on details of particular relevance to understanding the catalog's compiled parameters. We further describe and make available the digital HI line spectra associated with the cataloged sources. In addition to the extragalactic HI line detections, we report nine confirmed OH megamasers (OHMs) and 10 OHM candidates at 0.16<z<0.22 whose OH line signals are redshifted into the ALFALFA frequency band. Because of complexities in data collection and processing associated with the use of a feed-horn array on a complex single-dish antenna in the terrestrial radio frequency interference environment, we also present a list of suggestions and caveats for consideration by users of the ALFALFA extragalactic catalog for future scientific investigations.
- ID:
- ivo://CDS.VizieR/J/AJ/142/170
- Title:
- ALFALFA survey: the {alpha}.40 HI source catalog
- Short Name:
- J/AJ/142/170
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a current catalog of 21cm HI line sources extracted from the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA) survey over ~2800deg^2^ of sky: the {alpha}.40 catalog. Covering 40% of the final survey area, the {alpha}.40 catalog contains 15855 sources in the regions 07h30m<RA<16h30m, +04{deg}<DEC<+16{deg}, and +24{deg}<DEC<+28{deg} and 22h<RA<03h, +14{deg}<DEC<+16{deg}, and +24{deg}<DEC<+32{deg}. Of those, 15041 are certainly extragalactic, yielding a source density of 5.3 galaxies per deg^2^, a factor of 29 improvement over the catalog extracted from the HI Parkes All-Sky Survey. In addition to the source centroid positions, HI line flux densities, recessional velocities, and line widths, the catalog includes the coordinates of the most probable optical counterpart of each HI line detection, and a separate compilation provides a cross-match to identifications given in the photometric and spectroscopic catalogs associated with the Sloan Digital Sky Survey Data Release 7. Fewer than 2% of the extragalactic HI line sources cannot be identified with a feasible optical counterpart; some of those may be rare OH megamasers at 0.16<z<0.25. A detailed analysis is presented of the completeness, width-dependent sensitivity function and bias inherent of the {alpha}.40 catalog. The impact of survey selection, distance errors, current volume coverage, and local large-scale structure on the derivation of the HI mass function is assessed.
- ID:
- ivo://CDS.VizieR/J/AJ/139/2130
- Title:
- ALFA-ZOA precursor observation
- Short Name:
- J/AJ/139/2130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Arecibo L-band Feed Array (ALFA) is being used to conduct a low-Galactic latitude survey, to map the distribution of galaxies and large-scale structures behind the Milky Way through detection of galaxies' neutral hydrogen (HI) 21cm emission. This Zone of Avoidance (ZOA) survey finds new HI galaxies which lie hidden behind the Milky Way, and also provides redshifts for partially obscured galaxies known at other wavelengths. Before the commencement of the full survey, two low-latitude precursor regions were observed, totaling 138deg^2^, with 72 HI galaxies detected. Detections through the inner Galaxy generally have no cataloged counterparts in any other waveband, due to the heavy extinction and stellar confusion. Detections through the outer Galaxy are more likely to have Two Micron All Sky Survey counterparts. We present the results of these precursor observations, including a catalog of the detected galaxies, with their HI parameters.
- ID:
- ivo://CDS.VizieR/J/AJ/158/234
- Title:
- ALFAZOA Shallow Survey galaxy properties
- Short Name:
- J/AJ/158/234
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Arecibo L-band Feed Array Zone of Avoidance (ALFAZOA) Shallow Survey is a blind H I survey of the extragalactic sky behind the northern Milky Way conducted with the ALFA receiver on the 305 m Arecibo Radio Telescope. ALFAZOA Shallow covered 900 square degrees at full sensitivity from 30{deg}=<l=<75{deg} and |b|=<10{deg} and an additional 460 square degrees at limited sensitivity at latitudes up to 20{deg}. It has an rms sensitivity of 5-7 mJy and a velocity resolution of 9-20.6 km/s, and detected 403 galaxies out to a recessional velocity of 12000 km/s, with an angular resolution of 3.4' and a positional accuracy between 0.2' and 1.7'. The survey is complete above an integrated line flux of F_HI_=2.0 Jy km/s for half the survey, and above F_HI_= 2.8 Jy km/s for the other half. Of the ALFAZOA H I detections, 43% have at least one possible optical/near-infrared counterpart in the literature, and an additional 16% have counterparts that only included previous H I measurements. There are fewer counterparts in regions of high extinction and for galaxies with lower H I mass. Comparing the results of the survey to the predictions of Erdogdu et al. (2006MNRAS.373...45E), and using their nomenclature, ALFAZOA confirms the position and extent in the ZOA of the C7, C{zeta}, Pegasus, Corona Borealis, and Delphinus structures, but not of the Cygnus void. Two new structures are identified, both connected to the C7 overdensity; one extends to 35{deg}, and the other crosses the ZOA.
16. ALHAMBRA Survey
- ID:
- ivo://CDS.VizieR/J/MNRAS/441/2891
- Title:
- ALHAMBRA Survey
- Short Name:
- J/MNRAS/441/2891
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Advance Large Homogeneous Area Medium-Band Redshift Astronomical (ALHAMBRA) survey has observed eight different regions of the sky, including sections of the Cosmic Evolution Survey (COSMOS), DEEP2, European Large-Area Infrared Space Observatory Survey (ELAIS), Great Observatories Origins Deep Survey North (GOODS-N), Sloan Digital Sky Survey (SDSS) and Groth fields using a new photometric system with 20 optical, contiguous ~300{AA} filters plus the JHKs bands. The filter system is designed to optimize the effective photometric redshift depth of the survey, while having enough wavelength resolution for the identification of faint emission lines. The observations, carried out with the Calar Alto 3.5-m telescope using the wide-field optical camera Large Area Imager for Calar Alto (LAICA) and the near-infrared (NIR) instrument Omega-2000, represent a total of ~700h of on-target science images. Here we present multicolour point-spread function (PSF) corrected photometry and photometric redshifts for ~438000 galaxies, detected in synthetic F814W images. The catalogues are complete down to a magnitude I~24.5AB and cover an effective area of 2.79deg^2^. Photometric zero-points were calibrated using stellar transformation equations and refined internally, using a new technique based on the highly robust photometric redshifts measured for emission-line galaxies. We calculate Bayesian photometric redshifts with the Bayesian Photometric Redshift (bpz)2.0 code, obtaining a precision of {delta}z/(1+z_s_)=1 per cent for I<22.5 and {delta}z/(1+z_s_)=1.4 per cent for 22.5<I<24.5. The global n(z) distribution shows a mean redshift <z>=0.56 for I<22.5AB and <z>=0.86 for I<24.5AB. Given its depth and small cosmic variance, ALHAMBRA is a unique data set for galaxy evolution studies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/435/3444
- Title:
- ALHAMBRA survey morphological catalogue
- Short Name:
- J/MNRAS/435/3444
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) is photometric survey designed to trace the cosmic evolution and cosmic variance. It covers a large area of ~4deg^2^ in eight fields, where seven fields overlap with other surveys, allowing us to have complementary data in other wavelengths. All observations were carried out in 20 continuous, medium band (30nm width) optical and 3 near-infrared (JHK) bands, providing the precise measurements of photometric redshifts. In addition, morphological classification of galaxies is crucial for any kind of galaxy formation and cosmic evolution studies, providing the information about star formation histories, their environment and interactions, internal perturbations, etc. We present a morphological classification of >40000 galaxies in the ALHAMBRA survey. We associate to every galaxy a probability to be early type using the automated Bayesian code galsvm. Despite of the spatial resolution of the ALHAMBRA images (~1arcsec), for 22051 galaxies, we obtained the contamination by other type of less than 10 percent. Of those, 1640 and 10322 galaxies are classified as early- (down to redshifts ~0.5) and late-type (down to redshifts ~1.0), respectively, with magnitudes F_613W_<=22.0. In addition, for magnitude range 22.0<F_613W_<=23.0, we classified other 10089 late-type galaxies with redshifts <=1.3. We show that the classified objects populate the expected regions in the colour-mass and colour-magnitude planes. The presented data set is especially attractive given the homogeneous multiwavelength coverage available in the ALHAMBRA fields, and is intended to be used in a variety of scientific applications. The low-contamination catalogue (<10 percent) is made publicly available with this paper.
- ID:
- ivo://CDS.VizieR/J/ApJ/768/91
- Title:
- ALMA observations of LESS submm galaxies
- Short Name:
- J/ApJ/768/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 survey of 126 submillimeter sources from the LABOCA ECDFS Submillimeter Survey (LESS). Our 870{mu}m survey with ALMA (ALESS) has produced maps ~3x deeper and with a beam area ~200x smaller than the original LESS observations, doubling the current number of interferometrically-observed submillimeter sources. The high resolution of these maps allows us to resolve sources that were previously blended and accurately identify the origin of the submillimeter emission. We discuss the creation of the ALESS submillimeter galaxy (SMG) catalog, including the main sample of 99 SMGs and a supplementary sample of 32 SMGs. We find that at least 35% (possibly up to 50%) of the detected LABOCA sources have been resolved into multiple SMGs, and that the average number of SMGs per LESS source increases with LESS flux density. Using the (now precisely known) SMG positions, we empirically test the theoretical expectation for the uncertainty in the single-dish source positions. We also compare our catalog to the previously predicted radio/mid-infrared counterparts, finding that 45% of the ALESS SMGs were missed by this method. Our ~1.6" resolution allows us to measure a size of ~9kpcx5kpc for the rest-frame ~300{mu}m emission region in one resolved SMG, implying a star formation rate surface density of 80M_{sun}_/yr/kpc2, and we constrain the emission regions in the remaining SMGs to be <10kpc. As the first statistically reliable survey of SMGs, this will provide the basis for an unbiased multiwavelength study of SMG properties.
- ID:
- ivo://CDS.VizieR/J/ApJ/882/138
- Title:
- ALMA Spectroscopic Survey in the HUDF (ASPECS)
- Short Name:
- J/ApJ/882/138
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the results from the ALMA large program ASPECS, the spectroscopic survey in the Hubble Ultra Deep Field (HUDF), to constrain CO luminosity functions of galaxies and the resulting redshift evolution of {rho}(H_2_). The broad frequency range covered enables us to identify CO emission lines of different rotational transitions in the HUDF at z>1. We find strong evidence that the CO luminosity function evolves with redshift, with the knee of the CO luminosity function decreasing in luminosity by an order of magnitude from ~2 to the local universe. Based on Schechter fits, we estimate that our observations recover the majority (up to ~90%, depending on the assumptions on the faint end) of the total cosmic CO luminosity at z=1.0-3.1. After correcting for CO excitation, and adopting a Galactic CO-to-H_2_ conversion factor, we constrain the evolution of the cosmic molecular gas density {rho}(H_2_): this cosmic gas density peaks at z~1.5 and drops by a factor of 6.5_-1.4_^+1.8^ to the value measured locally. The observed evolution in {rho}(H_2_), therefore, closely matches the evolution of the cosmic star formation rate density {rho}SFR. We verify the robustness of our result with respect to assumptions on source inclusion and/or CO excitation. As the cosmic star formation history can be expressed as the product of the star formation efficiency and the cosmic density of molecular gas, the similar evolution of {rho}(H_2_) and {rho}SFR leaves only little room for a significant evolution of the average star formation efficiency in galaxies since z~3 (85% of cosmic history).
- ID:
- ivo://CDS.VizieR/J/ApJ/812/43
- Title:
- ALMA 870um obs. of HerMES galaxies
- Short Name:
- J/ApJ/812/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Herschel Multi-tiered Extragalactic Survey (HerMES, Oliver et al. 2012, VIII/95) has identified large numbers of dusty star-forming galaxies (DSFGs) over a wide range in redshift. A detailed understanding of these DSFGs is hampered by the limited spatial resolution of Herschel. We present 870{mu}m 0.45" resolution imaging obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) of a sample of 29 HerMES DSFGs that have far-infrared (FIR) flux densities that lie between the brightest of sources found by Herschel and fainter DSFGs found via ground-based surveys in the submillimeter region. The ALMA imaging reveals that these DSFGs comprise a total of 62 sources (down to the 5{sigma} point-source sensitivity limit in our ALMA sample; {sigma}~0.2mJy). Optical or near-infrared imaging indicates that 36 of the ALMA sources experience a significant flux boost from gravitational lensing ({mu}>1.1), but only six are strongly lensed and show multiple images. We introduce and make use of uvmcmcfit, a general-purpose and publicly available Markov chain Monte Carlo visibility-plane analysis tool to analyze the source properties. Combined with our previous work on brighter Herschel sources, the lens models presented here tentatively favor intrinsic number counts for DSFGs with a break near 8mJy at 880um and a steep fall-off at higher flux densities. Nearly 70% of the Herschel sources break down into multiple ALMA counterparts, consistent with previous research indicating that the multiplicity rate is high in bright sources discovered in single-dish submillimeter or FIR surveys. The ALMA counterparts to our Herschel targets are located significantly closer to each other than ALMA counterparts to sources found in the LABOCA ECDFS Submillimeter Survey. Theoretical models underpredict the excess number of sources with small separations seen in our ALMA sample. The high multiplicity rate and small projected separations between sources seen in our sample argue in favor of interactions and mergers plausibly driving both the prodigious emission from the brightest DSFGs as well as the sharp downturn above S880=8mJy.