- ID:
- ivo://CDS.VizieR/J/ApJ/706/158
- Title:
- Early-type galaxies in PEARS
- Short Name:
- J/ApJ/706/158
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) slitless grism spectra from the PEARS program, we study the stellar populations of morphologically selected early-type galaxies in the GOODS North and South fields. The sample - extracted from a visual classification of the (v2.0) HST/ACS images and restricted to redshifts z>0.4 - comprises 228 galaxies (i_F775W_<24mag, AB) out to z<~1.3 over 320arcmin^2^, with a median redshift z_M_=0.75. This work significantly increases our previous sample from the GRAPES survey in the HUDF (18 galaxies over ~11arcmin^2^). The grism data allow us to separate the sample into "red" and "blue" spectra, with the latter comprising 15% of the total. Three different grids of models parameterizing the star formation history are used to fit the low-resolution spectra.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/852/53
- Title:
- Early X-ray flares in GRBs
- Short Name:
- J/ApJ/852/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the early X-ray flares in the GRB "flare-plateau-afterglow" (FPA) phase observed by Swift-XRT. The FPA occurs only in one of the seven GRB subclasses: the binary-driven hypernovae (BdHNe). This subclass consists of long GRBs with a carbon-oxygen core and a neutron star (NS) binary companion as progenitors. The hypercritical accretion of the supernova (SN) ejecta onto the NS can lead to the gravitational collapse of the NS into a black hole. Consequently, one can observe a GRB emission with isotropic energy E_iso_>~10^52^erg, as well as the associated GeV emission and the FPA phase. Previous work had shown that gamma-ray spikes in the prompt emission occur at ~10^15^-10^17^cm with Lorentz Gamma factors {Gamma}~10^2^-10^3^. Using a novel data analysis, we show that the time of occurrence, duration, luminosity, and total energy of the X-ray flares correlate with Eiso. A crucial feature is the observation of thermal emission in the X-ray flares that we show occurs at radii ~10^12^cm with {Gamma}<~4. These model-independent observations cannot be explained by the "fireball" model, which postulates synchrotron and inverse-Compton radiation from a single ultrarelativistic jetted emission extending from the prompt to the late afterglow and GeV emission phases. We show that in BdHNe a collision between the GRB and the SN ejecta occurs at ~10^10^cm, reaching transparency at ~10^12^cm with {Gamma}<~4. The agreement between the thermal emission observations and these theoretically derived values validates our model and opens the possibility of testing each BdHN episode with the corresponding Lorentz Gamma factor.
- ID:
- ivo://CDS.VizieR/J/ApJ/796/60
- Title:
- ECDFS galaxies photometric redshifts & counterparts
- Short Name:
- J/ApJ/796/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). This work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) and the Taiwan ECDFS Near-Infrared Survey (TENIS) in addition to other data. We also revisit multi-wavelength counterparts for published X-ray sources from the 4Ms CDFS and 250ks ECDFS surveys, finding reliable counterparts for 1207 out of 1259 sources (~96%). Data used for photometric redshifts include intermediate-band photometry deblended using the TFIT method, which is used for the first time in this work. Photometric redshifts for X-ray source counterparts are based on a new library of active galactic nuclei/galaxy hybrid templates appropriate for the faint X-ray population in the CDFS. Photometric redshift accuracy for normal galaxies is 0.010 and for X-ray sources is 0.014 and outlier fractions are 4% and 5.2%, respectively. The results within the CANDELS coverage area are even better, as demonstrated both by spectroscopic comparison and by galaxy-pair statistics. Intermediate-band photometry, even if shallow, is valuable when combined with deep broadband photometry. For best accuracy, templates must include emission lines.
- ID:
- ivo://CDS.VizieR/J/A+A/492/637
- Title:
- Eddington ratios of faint AGN
- Short Name:
- J/A+A/492/637
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use one of the deepest spectroscopic samples of broad-line active galactic nuclei (AGN) currently available, extracted from the VIMOS VLT Deep Survey (VVDS, Cat. <III/250>), to compute the MgII and CIV virial-mass estimates of 120 super-massive black holes in the redshift range 1.0<z<1.9 and 2.6<z<4.3.
- ID:
- ivo://CDS.VizieR/J/ApJS/106/1
- Title:
- EFAR cluster and galaxy selection
- Short Name:
- J/ApJS/106/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The EFAR project is a study of 736 candidate elliptical galaxies in 84 clusters lying in two regions, toward Hercules-Corona Borealis and Perseus-Pisces-Cetus, at distances cz~6000-15000km/s. In this paper (the first of a series), we present an introduction to the EFAR project and describe in detail the selection of the clusters and galaxies in our sample. Fundamental data for the galaxies and clusters are given, including accurate new positions for each galaxy and redshifts for each cluster. The galaxy selection functions are determined by using diameters measured from Schmidt sky survey images for 2185 galaxies in the cluster fields. Future papers in this series will present the spectroscopic and photometric observations of this sample, investigate the properties of the fundamental plane for elliptical galaxies, and determine the large-scale peculiar velocity fields in these two regions of the universe.
- ID:
- ivo://CDS.VizieR/J/A+A/532/A74
- Title:
- EFIGI catalogue of 4458 nearby galaxies
- Short Name:
- J/A+A/532/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Now that large databases of resolved galaxy images are provided by modern imaging surveys, advanced morphological studies can be envisioned, urging for well defined calibration samples. We present the EFIGI catalogue, a multiwavelength database specifically designed for a dense sampling of all Hubble types. The catalogue merges data from standard surveys and catalogues (Principal Galaxy Catalogue, Sloan Digital Sky Survey, Value-Added Galaxy Catalogue, HyperLeda, and the NASA Extragalactic Database) and provides detailed morphological information. Imaging data are obtained from the SDSS DR4 release in the u, g, r, i, and z bands for a sample of 4458 PGC galaxies, whereas photometric and spectroscopic data are obtained from the SDSS DR5 catalogue. Point-Spread Function models are derived in all five bands. Composite colour images of all objects are visually examined by a group of astronomers, and galaxies are staged along the Hubble sequence and classified according to 16 morphological attributes describing their structure, texture, as well as environment and appearance on a five-level scale. The EFIGI Hubble sequence shows remarkable agreement with the RC3 Revised Hubble Sequence. The main characteristics and reliability of the catalogue are examined, including photometric completeness, type mix, systematic trends and correlations. The final EFIGI database is a large sub-sample of the local Universe, with a dense sampling of Sd, Sdm, Sm and Im types compared to magnitude-limited catalogues. We estimate the photometric catalogue to be more than ~80% complete for galaxies with 10<g<14. More than 99.5% of EFIGI galaxies have a known redshift in the HyperLeda and NED databases.
- ID:
- ivo://CDS.VizieR/J/ApJ/671/1355
- Title:
- EGRET blazars in VIPS
- Short Name:
- J/ApJ/671/1355
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the radio properties of EGRET-detected blazars observed as part of the VLBA Imaging and Polarimetry Survey (VIPS). VIPS has a flux limit roughly an order of magnitude below the MOJAVE survey and most other samples that have been used to study the properties of EGRET blazars. At lower flux levels, radio flux density does not directly correlate with gamma-ray flux density. We do find that the EGRET-detected blazars tend to have higher brightness temperatures, greater core fractions, and possibly larger than average jet opening angles. A weak correlation is also found with jet length and with polarization. All of the well-established trends can be explained by systematically larger Doppler factors in the gamma-ray-loud blazars, consistent with the measurements of higher apparent velocities found in monitoring programs carried out at radio frequencies above 10 GHz.
- ID:
- ivo://CDS.VizieR/J/ApJ/693/617
- Title:
- Ellipticities of cluster early-type galaxies
- Short Name:
- J/ApJ/693/617
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled a sample of early-type cluster galaxies from 0<z<1.3 and measured the evolution of their ellipticity distributions. Our sample contains 487 galaxies in 17 z>0.3 clusters with high-quality space-based imaging and a comparable sample of 210 galaxies in 10 clusters at z<0.05. We select early-type galaxies (elliptical and S0 galaxies) that fall within the cluster R_200_, and which lie on the red-sequence in the magnitude range -19.3>M_B_>-21, after correcting for luminosity evolution as measured by the fundamental plane.
- ID:
- ivo://CDS.VizieR/J/ApJ/871/258
- Title:
- ELQS in SDSS. III. The full ELQS quasar catalog
- Short Name:
- J/ApJ/871/258
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have designed the Extremely Luminous Quasar Survey (ELQS) to provide a highly complete census of unobscured UV-bright quasars during the cosmic noon, z=2.8-5.0. Here we report the discovery of 70 new quasars in the ELQS South Galactic Cap (ELQS-S) quasar sample, doubling the number of known extremely luminous quasars in 4237.3deg^2^ of the Sloan Digital Sky Survey footprint. These observations conclude the ELQS and we present the properties of the full ELQS quasar catalog, containing 407 quasars over 11838.5deg^2^. Our novel ELQS quasar selection strategy resulted in unprecedented completeness at the bright end and allowed us to discover 109 new quasars in total. This marks an increase of ~36% (109/298) in the known population at these redshifts and magnitudes, while we further are able to retain a selection efficiency of ~80%. On the basis of 166 quasars from the full ELQS quasar catalog, which adhere to the uniform criteria of the Two Micron All Sky Survey point source catalog, we measure the bright-end quasar luminosity function (QLF) and extend it one magnitude brighter than previous studies. Assuming a single power law with exponential density evolution for the functional form of the QLF, we retrieve the best-fit parameters from a maximum likelihood analysis. We find a steep bright-end slope of {beta}~-4.1, and we can constrain the bright-end slope to {beta}<=-3.4 with 99% confidence. The density is well modeled by the exponential redshift evolution, resulting in a moderate decrease with redshift ({gamma}~-0.4).
- ID:
- ivo://CDS.VizieR/J/ApJS/192/5
- Title:
- Emission-line galaxies from HETDEX pilot survey
- Short Name:
- J/ApJS/192/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of emission-line galaxies selected solely by their emission-line fluxes using a wide-field integral field spectrograph. This work is partially motivated as a pilot survey for the upcoming Hobby-Eberly Telescope Dark Energy Experiment. We describe the observations, reductions, detections, redshift classifications, line fluxes, and counterpart information for 397 emission-line galaxies detected over 169arcmin^2^ with a 3500-5800{AA} bandpass under 5{AA} full-width-half-maximum (FWHM) spectral resolution. The survey's best sensitivity for unresolved objects under photometric conditions is between 4 and 20x10^-17^erg/s/cm^2^ depending on the wavelength, and Ly{alpha} luminosities between 3x10^42^ and 6x10^42^erg/s are detectable. This survey method complements narrowband and color-selection techniques in the search of high-redshift galaxies with its different selection properties and large volume probed. The four survey fields within the COSMOS, GOODS-N, MUNICS, and XMM-LSS areas are rich with existing, complementary data. We find 105 galaxies via their high-redshift Ly{alpha} emission at 1.9<z<3.8, and the majority of the remainder objects are low-redshift [OII]3727 emitters at z<0.56. The classification between low- and high-redshift objects depends on rest-frame equivalent width (EW), as well as other indicators, where available. Based on matches to X-ray catalogs, the active galactic nuclei fraction among the Ly{alpha} emitters is 6%. We also analyze the survey's completeness and contamination properties through simulations. We find five high-z, highly significant, resolved objects with FWHM sizes >44arcmin^2^ which appear to be extended Ly{alpha} nebulae. We also find three high-z objects with rest-frame Ly{alpha} EW above the level believed to be achievable with normal star formation, EW0>240{AA}.
