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841. 3DHST CANDELS redshift compilation
ID:
ivo://CDS.VizieR/J/MNRAS/475/5133
Title:
3DHST CANDELS redshift compilation
Short Name:
J/MNRAS/475/5133
Date:
21 Oct 2021
Publisher:
CDS
Description:
We established an accurate comparison between observationally and theoretically estimated major merger rates over a large range of mass (logM_bar_/M_{sun}_=9.9-11.4) and redshift (z=0.7-1.6). For this, we combined a new estimate of the merger rate from an exhaustive count of pairs within the virial radius of massive galaxies at z~1.265 and cross-validated with their morphology, with estimates from the morpho-kinematic analysis of two other samples. Theoretical predictions were estimated using semi-empirical models with inputs matching the properties of the observed samples, while specific visibility time-scales scaled to the observed samples were used. Both theory and observations are found to agree within 30 per cent of the observed value, which provides strong support to the hierarchical assembly of galaxies over the probed ranges of mass and redshift. Here, we find that ~60 per cent of population of local massive (M_stellar_=10^10.3-11.6^M_{sun}_) galaxies would have undergone a wet major merger since z=1.5, consistently with previous studies. Such recent mergers are expected to result in the (re-)formation of a significant fraction of local disc galaxies.
842. 3D-HST Survey: grism spectra master catalog
ID:
ivo://CDS.VizieR/J/ApJS/225/27
Title:
3D-HST Survey: grism spectra master catalog
Short Name:
J/ApJS/225/27
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present reduced data and data products from the 3D-HST survey, a 248-orbit HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 H_140_ imaging, parallel ACS G800L spectroscopy, and parallel I_814_ imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton+ (2014, J/ApJS/214/24) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22548 unique objects down to JH_IR_<=24 (79609 unique objects down to JH_IR<=26). Of these, 5459 galaxies are at z>1.5 and 9621 are at 0.7<z<1.5, where H{alpha} falls in the G141 wavelength coverage. The typical redshift error for JH_IR_<=24 galaxies is {sigma}_z_~0.003x(1+z), i.e., one native WFC3 pixel. The 3{sigma} limit for emission line fluxes of point sources is 2.1x10^-17^erg/s/cm^2^.
843. Diameter-limited Northern sky galaxies catalog
ID:
ivo://CDS.VizieR/J/AN/316/39
Title:
Diameter-limited Northern sky galaxies catalog
Short Name:
J/AN/316/39
Date:
21 Oct 2021
Publisher:
CDS
Description:
In order to understand if the differences between the SSRS of Da Costa et al. (1988ApJ...327..544D) (which is diameter limited) and the CfA survey (Huchra et al., 1995, Cat. <VII/193>) (which is magnitude limited) are real or induced by the different selection criteria, the CfA survey has been directly compared with a diameter-limited sample covering the same region of the sky (UDLS, Bardelli et al., 1991A&A...248..354B, Zucca et al., 1991MNRAS.253..401Z). In this paper we present the data for the galaxies in the UDLS sample, in an updated version which collects velocity information from the literature until June 1993, leaving us with a velocity completeness better than ~95%.
844. 8620 DIB equivalent width and extinction
ID:
ivo://CDS.VizieR/J/MNRAS/463/2653
Title:
8620 DIB equivalent width and extinction
Short Name:
J/MNRAS/463/2653
Date:
21 Oct 2021
Publisher:
CDS
Description:
The young stellar cluster Westerlund 1 (Wd 1: l=339.6, b=-0.4) is one of the most massive in the local Universe, but accurate parameters are pending on better determination of its extinction and distance. Based on our photometry and data collected from other sources, we have derived a reddening law for the cluster line-of-sight representative of the Galactic plane (-5{deg}<b<+5{deg}) in the window 0.4-4.8um. The power-law exponent alpha=2.13+/-0.08 is much steeper than those published a decade ago (1.6-1.8) and our index RV=2.50+/-0.04 also differs from them, but in very good agreement with recent works based on deep surveys in the inner Galaxy. As a consequence, the total extinction AKs=0.74+/-0.08 (AV=11.40+/-2.40) is substantially smaller than previous results (0.91-1.13), part of which (AKs=0.63 or AV=9.66) is from the interstellar medium. The extinction in front of the cluster spans a range of AV~8.7 with a gradient increasing from SW to NE across the cluster face, following the same general trend of warm dust distribution. The map of the J-Ks colour index also shows a trend of reddening in this direction. We measured the equivalent width of the diffuse interstellar band at 8620 A (the 'GAIA DIB') for Wd 1 cluster members and derived the relation AKs=0.612EW-0.191EW^2^. This extends the Munari et al. relation, valid for E(B-V)<1, to the non-linear regime (AV>4).
845. Diffuse ionized gas database DIGEDA
ID:
ivo://CDS.VizieR/J/other/RMxAA/45.261
Title:
Diffuse ionized gas database DIGEDA
Short Name:
J/other/RMxAA/45
Date:
21 Oct 2021
Publisher:
CDS
Description:
Studies of the Diffuse Ionized Gas (DIG) have progressed without providing so far any strict criterion to distinguish DIGs from HII regions. In this work, we compile the emission line measurements of 29 galaxies that are available in the scientific literature, thereby setting up the first DIG database DIGEDA. Making use of this database, we proceeded to analyze global properties of the DIG using the [NII]6583/Halpha, [OI]6300/Halpha, [OIII]5007/Hbeta and [SII]6716/Halpha lines ratios, including the Halpha emission measure. This analysis leads us to conclude that the [NII]/Halpha ratio provides an objective criterion for distinguishing whether an emission region is DIG or an HII region, while the EM(Halpha) is a useful quantity only when the galaxies are considered individually. Finally, we find that the emission regions of Irr galaxies classified as DIG in the literature appear in fact to be much more similar to HII regions than to the DIGs of spiral galaxies.
846. Diffuse ionized gas in the Antennae galaxy
ID:
ivo://CDS.VizieR/J/A+A/611/A95
Title:
Diffuse ionized gas in the Antennae galaxy
Short Name:
J/A+A/611/A95
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Antennae galaxy (NGC 4038/39) is the closest major interacting galaxy system and is therefore often studied as a merger prototype. We present the first comprehensive integral field spectroscopic dataset of this system, observed with the MUSE instrument at the ESO VLT. We cover the two regions in this system which exhibit recent star formation: the central galaxy interaction and a region near the tip of the southern tidal tail. In these fields, we detect HII regions and diffuse ionized gas to unprecedented depth. About 15% of the ionized gas was undetected by previous observing campaigns. This newly detected faint ionized gas is visible everywhere around the central merger, and shows filamentary structure. We estimate diffuse gas fractions of about 60% in the central field and 10% in the southern region. We are able to show that the southern region contains a significantly different population of HII regions, showing fainter luminosities. By comparing HII region luminosities with the HST catalog of young star clusters in the central field, we estimate that there is enough Lyman-continuum leakage in the merger to explain the amount of diffuse ionized gas that we detect. We compare the Lyman-continuum escape fraction of each HII region against emission line ratios that are sensitive to the ionization parameter. While we find no systematic trend between these properties, the most extreme line ratios seem to be strong indicators of density bounded ionization. Extrapolating the Lyman-continuum escape fractions to the southern region, we conclude that simply from the comparison of the young stellar populations to the ionized gas there is no need to invoke other ionization mechanisms than Lyman-continuum leaking HII regions for the diffuse ionized gas in the Antennae.
847. Diffuse neutral hydrogen in HIPASS
ID:
ivo://CDS.VizieR/J/A+A/533/A122
Title:
Diffuse neutral hydrogen in HIPASS
Short Name:
J/A+A/533/A122
Date:
21 Oct 2021
Publisher:
CDS
Description:
Observations of neutral hydrogen can provide a wealth of information about the distribution and kinematics of galaxies. To learn more about large scale structures and accretion processes, the extended environment of galaxies must also be observed. Numerical simulations predict a cosmic web of extended structures and gaseous filaments. To detect HI beyond the ionisation edge of galaxy disks, column density sensitivities have to be achieved that probe the regime of Lyman limit systems. Typically HI observations are limited to a brightness sensitivity of N_HI_~10^19^cm^-2^ but this has to be improved by at least an order of magnitude.
848. Diffuse X-ray-emitting gas in major mergers
ID:
ivo://CDS.VizieR/J/AJ/155/81
Title:
Diffuse X-ray-emitting gas in major mergers
Short Name:
J/AJ/155/81
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using archived data from the Chandra X-ray telescope, we have extracted the diffuse X-ray emission from 49 equal-mass interacting/merging galaxy pairs in a merger sequence, from widely separated pairs to merger remnants. After the removal of contributions from unresolved point sources, we compared the diffuse thermal X-ray luminosity from hot gas (L_X_(gas)) with the global star formation rate (SFR). After correction for absorption within the target galaxy, we do not see a strong trend of L_X_(gas)/SFR with the SFR or merger stage for galaxies with SFR>1 M_{sun}_/yr. For these galaxies, the median L_X_(gas)/SFR is 5.5x10^39^ ((erg/s)/M_{sun}_/yr), similar to that of normal spiral galaxies. These results suggest that stellar feedback in star-forming galaxies reaches an approximately steady-state condition, in which a relatively constant fraction of about 2% of the total energy output from supernovae and stellar winds is converted into X-ray flux. Three late-stage merger remnants with low SFRs and high K-band luminosities (L_K_) have enhanced L_X_(gas)/SFR; their UV/IR/optical colors suggest that they are post-starburst galaxies, perhaps in the process of becoming ellipticals. Systems with L_K_<10^10^ L_{sun}_ have lower L_X_(gas)/SFR ratios than the other galaxies in our sample, perhaps due to lower gravitational fields or lower metallicities. We see no relation between L_X_(gas)/SFR and Seyfert activity in this sample, suggesting that feedback from active galactic nuclei is not a major contributor to the hot gas in our sample galaxies.
849. Digitized Sky Survey
ID:
ivo://eso.org/dss
Title:
Digitized Sky Survey
Short Name:
DSS ESO
Date:
05 Jul 2021 08:18:13
Publisher:
ESO
Description:
The Online Digitized Sky Surveys (DSS1 & 2) server at the ESO/ST-ECF Archive provides access to the CD-ROM set produced by the Space Telescope Science Institute through its Guide Star Survey group. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions. The photographic plates were scanned to a pixel scale of about 1.7 arcseconds per pixel for the POSS, SERC, and Palomar Quick-V surveys, and to about 1.0 arcseconds per pixel for the POSS-II surveys. Images of any part of the sky may be extracted from the DSS, in either FITS or GIF format.
850. Dimensionless coordinate distances
ID:
ivo://CDS.VizieR/J/ApJ/677/1
Title:
Dimensionless coordinate distances
Short Name:
J/ApJ/677/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We extend and apply a model-independent analysis method developed earlier by Daly & Djorgovski (2003ApJ...597....9D and 2004, Cat. <J/ApJ/612/652>) to new supernova, radio galaxy, and galaxy cluster samples to study the acceleration history of the universe and the properties of the dark energy. There is good agreement between results obtained with radio galaxies and supernovae, suggesting that both distance indicators are reliable. The deceleration parameter q(z) is obtained assuming only the validity of the FRW metric, allowing for a range of values of space curvature, and independent of a gravity theory and the physical nature of the contents of the universe. We show that q_0_ is independent of space curvature, and obtain q_0_=-0.48+/-0.11. The transition redshift when q_0_=0 is z_T_=0.78^+0.08^_-0.27_ for zero space curvature, and has a weak dependence on space curvature. We find good agreement between model-independent quantities and those predicted by general relativity, indicating that GR provides a good description of the data over look-back times of ten billion years.

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