- ID:
- ivo://CDS.VizieR/J/ApJS/233/3
- Title:
- The VLBA Extragalactic Proper Motion Catalog
- Short Name:
- J/ApJS/233/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of extragalactic proper motions created using archival VLBI data and our own VLBA astrometry. The catalog contains 713 proper motions, with average uncertainties of ~24{mu}as/yr, including 40 new or improved proper motion measurements using relative astrometry with the VLBA. The observations were conducted in the X-band and yielded positions with uncertainties of ~70{mu}as. We add 10 new redshifts using spectroscopic observations taken at Apache Point Observatory and Gemini North. With the VLBA Extragalactic Proper Motion Catalog, we detect the secular aberration drift-the apparent motion of extragalactic objects caused by the solar system's acceleration around the Galactic center-at a 6.3{sigma} significance. We model the aberration drift as a spheroidal dipole, with the square root of the power equal to 4.89+/-0.77{mu}as/yr, an amplitude of 1.69+/-0.27{mu}as/yr, and an apex at (275.2{deg}+/-10.0{deg}, -29.4{deg}+/-8.8{deg}). Our dipole model detects the aberration drift at a higher significance than some previous studies, but at a lower amplitude than expected or previously measured. The full aberration drift may be partially removed by the no-net-rotation constraint used when measuring archival extragalactic radio source positions. Like the cosmic microwave background dipole, which is induced by the observer's motion, the aberration drift signal should be subtracted from extragalactic proper motions in order to detect cosmological proper motions, including the Hubble expansion, long-period stochastic gravitational waves, and the collapse of large-scale structure.
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- ID:
- ivo://CDS.VizieR/J/ApJ/708/1076
- Title:
- The WHIQII survey: compact blue galaxies
- Short Name:
- J/ApJ/708/1076
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of the WIYN High Image Quality Indiana-Irvine (WHIQII) survey, we present 123 spectra of faint emission-line galaxies, selected to focus on intermediate redshift (0.4<~z<~0.8) galaxies with blue colors that appear physically compact on the sky. The sample includes 15 true Luminous Compact Blue Galaxies (LCBGs) and an additional 27 slightly less extreme emission-line systems. These galaxies represent a highly evolving class that may play an important role in the decline of star formation since z~1, but their exact nature and evolutionary pathways remain a mystery. Here, we use emission lines to determine metallicities and ionization parameters, constraining their intrinsic properties and state of star formation. Some LCBG metallicities are consistent with a "bursting dwarf" scenario, while a substantial fraction of others are not, further confirming that LCBGs are a highly heterogeneous population but are broadly consistent with the intermediate redshift field. In agreement with previous studies, we observe overall evolution in the luminosity-metallicity relation at intermediate redshift. Our sample, and particularly the LCBGs, occupies a region in the empirical R_23_-O_32_ plane that differs from luminous local galaxies and is more consistent with dwarf irregulars at the present epoch, suggesting that cosmic "downsizing" is observable in even the most fundamental parameters that describe star formation.
- ID:
- ivo://CDS.VizieR/J/ApJ/716/348
- Title:
- The XMM-Newton survey of the COSMOS field
- Short Name:
- J/ApJ/716/348
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the final optical identifications of the medium-depth (~60ks), contiguous (2deg^2^) XMM-Newton survey of the COSMOS field. XMM-Newton has detected ~1800 X-ray sources down to limiting fluxes of ~5x10^-16^, ~3x10^-15^, and ~7x10^-15^erg/cm^2^/s in the 0.5-2keV, 2-10keV, and 5-10keV bands, respectively (~1x10^-15^, ~6x10^-15^, and ~1x10^-14^erg/cm^2^/s, in the three bands, respectively, over 50% of the area). The work is complemented by an extensive collection of multiwavelength data from 24um to UV, available from the COSMOS survey, for each of the X-ray sources, including spectroscopic redshifts for >~50% of the sample, and high-quality photometric redshifts for the rest. The XMM and multiwavelength flux limits are well matched: 1760 (98%) of the X-ray sources have optical counterparts, 1711 (~95%) have IRAC counterparts, and 1394 (~78%) have MIPS 24um detections. Spectroscopically identified obscured and unobscured AGNs, as well as normal and star-forming galaxies, present well-defined optical and infrared properties. We devised a robust method to identify a sample of ~150 high-redshift (z>1), obscured AGN candidates for which optical spectroscopy is not available.
- ID:
- ivo://CDS.VizieR/J/ApJS/184/218
- Title:
- The zCOSMOS 10k-bright spectroscopic sample
- Short Name:
- J/ApJS/184/218
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic redshifts of a large sample of galaxies with I_AB_<22.5 in the COSMOS field, measured from spectra of 10644 objects that have been obtained in the first two years of observations in the zCOSMOS-bright redshift survey. These include a statistically complete subset of 10109 objects. The average accuracy of individual redshifts is 110km/s, independent of redshift. The reliability of individual redshifts is described by a Confidence Class that has been empirically calibrated through repeat spectroscopic observations of over 600 galaxies. There is very good agreement between spectroscopic and photometric redshifts for the most secure Confidence Classes. For the less secure Confidence Classes, there is a good correspondence between the fraction of objects with a consistent photometric redshift and the spectroscopic repeatability, suggesting that the photometric redshifts can be used to indicate which of the less secure spectroscopic redshifts are likely right and which are probably wrong, and to give an indication of the nature of objects for which we failed to determine a redshift. Using this approach, we can construct a spectroscopic sample that is 99% reliable and which is 88% complete in the sample as a whole, and 95% complete in the redshift range 0.5<z<0.8. The luminosity and mass completeness levels of the zCOSMOS-bright sample of galaxies is also discussed.
- ID:
- ivo://CDS.VizieR/J/ApJ/810/14
- Title:
- Third catalog of LAT-detected AGNs (3LAC)
- Short Name:
- J/ApJ/810/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It is based on the third Fermi-LAT catalog (3FGL) of sources detected between 100MeV and 300GeV with a Test Statistic greater than 25, between 2008 August 4 and 2012 July 31. The 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{deg}), a 71% increase over the second catalog based on 2 years of data. There are 28 duplicate associations, thus 1563 of the 2192 high-latitude gamma-ray sources of the 3FGL catalog are AGNs. Most of them (98%) are blazars. About half of the newly detected blazars are of unknown type, i.e., they lack spectroscopic information of sufficient quality to determine the strength of their emission lines. Based on their gamma-ray spectral properties, these sources are evenly split between flat-spectrum radio quasars (FSRQs) and BL Lacs. The most abundant detected BL Lacs are of the high-synchrotron-peaked (HSP) type. About 50% of the BL Lacs have no measured redshifts. A few new rare outliers (HSP-FSRQs and high-luminosity HSP BL Lacs) are reported. The general properties of the 3LAC sample confirm previous findings from earlier catalogs. The fraction of 3LAC blazars in the total population of blazars listed in BZCAT remains non-negligible even at the faint ends of the BZCAT-blazar radio, optical, and X-ray flux distributions, which hints that even the faintest known blazars could eventually shine in gamma-rays at LAT-detection levels. The energy-flux distributions of the different blazar populations are in good agreement with extrapolation from earlier catalogs.
- ID:
- ivo://CDS.VizieR/J/ApJ/869/6
- Title:
- Tidal interactions and mergers in EDisCS clusters
- Short Name:
- J/ApJ/869/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the fraction of tidal interactions and mergers (TIMs) with well-identified observability timescales (f_TIM_) in group, cluster, and accompanying field galaxies and its dependence on redshift (z), cluster velocity dispersion ({sigma}), and environment analyzing Hubble Space Telescope/ACS images and catalogs from the ESO Distant Cluster Survey. Our sample consists of 11 clusters, seven groups, and accompanying field galaxies at 0.4<=z<=0.8. We derive f_TIM_ using both a visual classification of galaxy morphologies and an automated method, the G-M_20_ method. We calibrate this method using the visual classifications that were performed on a subset of our sample. We find marginal evidence for a trend between f_TIM_ and z, in that higher z values correspond to higher f_TIM_. However, we also cannot rule out the null hypothesis of no correlation at higher than 68% confidence. No trend is present between f_TIM_ and {sigma}. We find that f_TIM_ shows suggestive peaks in groups, and tentatively in clusters at R>0.5xR_200_, implying that f_TIM_ gets boosted in these intermediate-density environments. However, our analysis of the local densities of our cluster sample does not reveal a trend between f_TIM_ and density, except for a potential enhancement at the very highest densities. We also perform an analysis of projected radius-velocity phase space for our cluster members. Our results reveal that TIM and undisturbed galaxies only have a 6% probability of having been drawn from the same parent population in their velocity distribution and 37% in radii, in agreement with the modest differences obtained in f_TIM_ at the clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/127/3121
- Title:
- TKRS catalog of GOODS-North Field
- Short Name:
- J/AJ/127/3121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of an extensive imaging and spectroscopic survey in the Great Observatories Origins Deep Survey (GOODS)-North field completed using DEIMOS on the Keck II telescope. Observations of 2018 targets in a magnitude-limited sample of 2911 objects to R_AB_=24.4 yield secure redshifts for a sample of 1440 galaxies and active galactic nuclei (AGNs) plus 96 stars. In addition to redshifts and associated quality assessments, our catalog also includes photometric and astrometric measurements for all targets detected in our R-band imaging survey of the GOODS-North region.
- ID:
- ivo://CDS.VizieR/J/ApJ/653/1027
- Title:
- TKRS/GOODS-N Field galaxies
- Short Name:
- J/ApJ/653/1027
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present kinematic measurements of a large sample of galaxies from the Team Keck Redshift Survey in the GOODS-N field. We measure line-of-sight velocity dispersions from integrated emission for 1089 galaxies with median redshift 0.637 and spatially resolved kinematics for a subsample of 380 galaxies. This is the largest sample of galaxies to z~1 with kinematics to date and allows us to measure kinematic properties without morphological pre-selection. Emission-line widths provide a dynamical measurement for the bulk of blue galaxies. To fit the spatially resolved kinematics, we construct models that fit both line-of-sight rotation amplitude and velocity dispersion. Integrated line width correlates well with a combination of the velocity gradient and dispersion and is a robust measure of galaxy kinematics.
- ID:
- ivo://CDS.VizieR/J/AJ/157/194
- Title:
- Total ALFALFA H I fluxes for extended sources
- Short Name:
- J/AJ/157/194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A procedure is presented to improve on measurement of total H I fluxes for extended sources in the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA) survey of neutral hydrogen sources in the nearby universe. A number of tests of the procedure are detailed, and we verify that we recover all of the flux measured with much larger telescope beams. Total fluxes are reported for all sources (1) exceeding 10 Jy km/s in the {alpha}.100 catalog (Haynes et al. 2018ApJ...861...49H), or (2) with Uppsala General Catalog (Cat. VII/26) diameters 3.0 arcmin or more, or (3) ALFALFA pipeline isophotal ellipse area more than 3.0 times the Arecibo beam. Total fluxes are also provided for a number of confused pairs and small groups including one or more of those high-flux sources. These data should be of use in baryonic Tully-Fisher studies and other applications where the measurement of the total reservoir of neutral atomic gas is important.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A147
- Title:
- Transient processing and analysis using AMPEL
- Short Name:
- J/A+A/631/A147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Both multi-messenger astronomy and new high-throughput wide-field surveys require flexible tools for the selection and analysis of astrophysical transients. Here we introduce the alert management, photometry, and evaluation of light curves (AMPEL) system, an analysis framework designed for high-throughput surveys and suited for streamed data. AMPEL combines the functionality of an alert broker with a generic framework capable of hosting user-contributed code; it encourages provenance and keeps track of the varying information states that a transient displays. The latter concept includes information gathered over time and data policies such as access or calibration levels. We describe a novel ongoing real-time multi-messenger analysis using AMPEL to combine IceCube neutrino data with the alert streams of the Zwicky Transient Facility (ZTF). We also reprocess the first four months of ZTF public alerts, and compare the yields of more than 200 different transient selection functions to quantify efficiencies for selecting Type Ia supernovae that were reported to the Transient Name Server (TNS). We highlight three channels suitable for (1) the collection of a complete sample of extragalactic transients, (2) immediate follow-up of nearby transients, and (3) follow-up campaigns targeting young, extragalactic transients. We confirm ZTF completeness in that all TNS supernovae positioned on active CCD regions were detected. AMPEL can assist in filtering transients in real time, running alert reaction simulations, the reprocessing of full datasets as well as in the final scientific analysis of transient data. This is made possible by a novel way of capturing transient information through sequences of evolving states, and interfaces that allow new code to be natively applied to a full stream of alerts. This text also introduces a method by which users can design their own channels for inclusion in the AMPEL live instance that parses the ZTF stream and the real-time submission of high-quality extragalactic supernova candidates to the TNS.
