- 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^.
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- 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%.
- 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).
- 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.
- 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.
- 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.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/612/652
- Title:
- Dimensionless coordinate distances to supernovae
- Short Name:
- J/ApJ/612/652
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Understanding the nature of dark energy, which appears to drive the expansion of the universe, is one of the central problems of physical cosmology today. In an earlier paper (Daly & Djorgovski, 2003ApJ...597....9D) we proposed a novel method to determine the expansion rate E(z) and the deceleration parameter q(z) in a largely model-independent way, directly from the data on coordinate distances y(z). Here we expand this methodology to include measurements of the pressure of dark energy p(z), its normalized energy density fraction f(z), and the equation-of-state parameter w(z). We then apply this methodology to a new, combined data set of distances to supernovae and radio galaxies.
- ID:
- ivo://CDS.VizieR/J/AJ/122/1383
- Title:
- DIRECT BVI photometry in M31
- Short Name:
- J/AJ/122/1383
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- DIRECT is a project to directly obtain the distances to two important galaxies in the cosmological distance ladder, M31 and M33, using detached eclipsing binaries and Cepheids. As part of our search for these variables, we have obtained photometry and positions for thousands of stellar objects within the monitored fields, covering an area of 557.8arcmin^2^. Here we present the equatorial coordinates and BVI photometry for 26,712 stars in the M31 galaxy, along the eastern arm and in the vicinity of the star-forming region NGC 206.
