- ID:
- ivo://CDS.VizieR/J/ApJS/208/7
- Title:
- Sodium excess objects. I. SDSS-DR7
- Short Name:
- J/ApJS/208/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Several studies have reported the presence of sodium excess objects having neutral atomic absorption lines at 5895{AA} (Na.D) and 8190{AA} that are deeper than expected based on stellar population models that match the stellar continuum. The origin of these lines is therefore hotly debated. van Dokkum & Conroy (2010Natur.468..940V) proposed that low-mass stars (<~0.3M_{sun}_) are more prevalent in massive early-type galaxies, which may lead to a strong Na I 8190 line strength. It is necessary to test this prediction, however, against other prominent optical line indices such as Na.D, Mg b, and Fe 5270, which can be measured with a significantly higher signal-to-noise ratio than Na I 8190. We identified a new sample of roughly 1000 Na.D excess objects (NEOs; ~8% of galaxies in the sample) based on Na.D line strength in the redshift range 0.00<=z<=0.08 from the Sloan Digital Sky Survey (SDSS) DR7 through detailed analysis of galaxy spectra. We explore the properties of these new objects here. The novelty of this work is that the galaxies were carefully identified through direct visual inspection of SDSS images, and we systematically compared the properties of NEOs and those of a control sample of galaxies with normal Na.D line strengths. We note that the majority of galaxies with high velocity dispersions ({sigma}_e_>250km/s) show Na.D excesses.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/368/797
- Title:
- Soft X-ray properties of Seyfert galaxies
- Short Name:
- J/A+A/368/797
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of ROSAT detected sources in the sample of spectroscopically selected Seyfert 1 and Seyfert 2 galaxies of Rafanelli et al. (1995AJ....109.1546R). The catalogue contains 102 Seyfert 1 and 36 Seyfert 2 galaxies. The identification is based on X-ray contour maps overlaid on optical images taken from the Digitized Sky Survey. We have derived the basic spectral and timing properties of the X-ray detected Seyfert galaxies. For Seyfert 1 galaxies a strong correlation between photon index and X-ray luminosity is detected. We confirm the presence of generally steeper X-ray continua in narrow-line Seyfert 1 galaxies (NLS1s) compared to broad-line Seyfert 1 galaxies. Seyfert 2 galaxies show photon indices similar to those of NLS1s. Whereas a tendency for an increasing X-ray luminosity with increasing interaction strength is found for Seyfert 1 galaxies, such a correlation is not found for Seyfert 2 galaxies. For Seyfert 1 galaxies we found also a strong correlation for increasing far-infrared luminosity with increasing interaction strength. Both NLS1s and Seyfert 2 galaxies show the highest values of far-infrared luminosity compared to Seyfert 1 galaxies, suggesting that NLS1s and Seyfert 2 galaxies host strong (circumnuclear) star formation. For variable Seyfert galaxies we present the X-ray light curves obtained from the ROSAT All-Sky Survey and from ROSAT PSPC and HRI pointed observations. Besides the expected strong short- and long-term X-ray variability in Seyfert 1 galaxies, we find indications for X-ray flux variations in Seyfert 2 galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/897/5
- Title:
- 90 sources radio flux density from GLEAM and HERA
- Short Name:
- J/ApJ/897/5
- Date:
- 16 Mar 2022 00:49:20
- Publisher:
- CDS
- Description:
- The central challenge in 21cm cosmology is isolating the cosmological signal from bright foregrounds. Many separation techniques rely on the accurate knowledge of the sky and the instrumental response, including the antenna primary beam. For drift-scan telescopes, such as the Hydrogen Epoch of Reionization Array (HERA), that do not move, primary beam characterization is particularly challenging because standard beam-calibration routines do not apply (Cornwell et al.) and current techniques require accurate source catalogs at the telescope resolution. We present an extension of the method from Pober et al. where they use beam symmetries to create a network of overlapping source tracks that break the degeneracy between source flux density and beam response and allow their simultaneous estimation. We fit the beam response of our instrument using early HERA observations and find that our results agree well with electromagnetic simulations down to a -20dB level in power relative to peak gain for sources with high signal-to-noise ratio. In addition, we construct a source catalog with 90 sources down to a flux density of 1.4Jy at 151MHz.
- ID:
- ivo://CDS.VizieR/J/A+AS/110/371
- Title:
- Southern binary galaxies. I.
- Short Name:
- J/A+AS/110/371
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+AS/125/329
- Title:
- Southern binary galaxies radial velocities
- Short Name:
- J/A+AS/125/329
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectrophotometry of a sample of 26 Southern binary galaxies. 17 pairs were confirmed to be physically associated with typical separation of 136h^-1^kpc. Pairs with velocity difference {DELTA}V>=600km/s are probably not physically bound. A comparison with field galaxies suggests that galaxies in pairs tend to have a younger population probably stimulated by tidal interaction. No correlation between the young population and projected separation was found. This table contains the quantities derived from the spectral data.
- ID:
- ivo://CDS.VizieR/J/other/ApL/30.1
- Title:
- Southern catalogue of isolated pairs extension
- Short Name:
- J/other/ApL/30.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper presents a sample of double galaxies selected from The Surface Photometry Catalog of the ESO-Uppsala Galaxies (Cat. <VII/115>) using the Karachentsev (1972: K72, Cat. <VII/77>) criteria. Considering the large and growing number of observing facilities in that hemisphere, the sample aims to supply investigators with targets as homogeneous as possible to those in the Northern Catalog of Isolated Pairs of Galaxies (K72) which have been studied in a large frequency range. The paper discusses the sample degree of completeness, separation and velocity distributions. First inferences are sketched from the morphological association of pair members and from the study of the Holmberg effect. Being the primary purpose of the paper to provide a tool to investigators, an Atlas of images for the 301 best candidate pairs obtained using the Digitized Sky Survey (The Digitized Sky Survey was produced at the Space Telescope Science Institute (ST ScI) under U.S. Government grant NAG W-2166) is given. The Atlas reports for each pair member the relevant data as obtained from the current literature.
- ID:
- ivo://CDS.VizieR/J/ApJS/80/137
- Title:
- Southern Extragalactic Radio Sources
- Short Name:
- J/ApJS/80/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains a list of 384 extragalactic radio sources south of declination -30{deg} which have been imaged with the Molonglo Observatory Synthesis Telescope (MOST) at 843 MHz with a HPBW of 44" x 44" cosec(dec). The sample includes those sources noted in the Molonglo Reference Catalog (MRC) (Cat.<VIII/16>) as extended (larger than 1'), as well as those noted as multiple (within 8' of another ssource and possibly related). The sample is representative of the strong extended extragalactic radio sources of the southern sky, but is not statistically complete. Positions, flux densities, and sizes are given for all sources, and those sources which have been confirmed as extended MRC sources are flagged. In addition, optical positions, magnitudes, redshifts, and identifications are given for 201 of the sources. These data were originally published in two tables which have been merged in this version.
- ID:
- ivo://CDS.VizieR/VII/116
- Title:
- Southern Galaxy Catalogue (SGC)
- Short Name:
- VII/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (Abstract in the documentation file "docu.txt") The "Southern Galaxy Catalogue" provides a finding list of galaxies larger than about 1.5 to 2 arc minutes, south of declination -17 degrees. It includes, as far as possible, precise positions, morphological types, luminosity classifications, and diameters. It is essentially complete for logD>1.52.
- ID:
- ivo://CDS.VizieR/J/MNRAS/400/1962
- Title:
- Southern GEMS groups. II.
- Short Name:
- J/MNRAS/400/1962
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the neutral hydrogen (HI) content of 16 groups for which we have multiwavelength data including X-ray observations. Wide-field imaging of the groups was obtained with the 20cm multibeam system on the 64m Parkes telescope. We have detected 10 previously uncatalogued HI sources, one of which has no visible optical counterpart. We examine the HI properties of the groups, compared to their X-ray characteristics, finding that those groups with a higher X-ray temperature and luminosity contain less HI per galaxy.
- ID:
- ivo://CDS.VizieR/J/AZh/77/569
- Title:
- Southern isolated triple systems of galaxies
- Short Name:
- J/AZh/77/569
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the ESO/SERC and POSS-I surveys we selected 76 isolated triple systems of galaxies with DE<-3{deg}. For each triplet the equatorial coordinates, type of configuration, angular diameters, apparent angular separation of the components, morphological types, total magnitudes and other characteristics are presented.
