- ID:
- ivo://CDS.VizieR/J/MNRAS/476/5216
- Title:
- Thick disc probability of GALAH stars
- Short Name:
- J/MNRAS/476/5216
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the GALAH pilot survey, we determine properties of the Galactic thin and thick discs near the solar neighbourhood. The data cover a small range of Galactocentric radius (7.9<~R_GC_<~9.5kpc), but extend up to 4kpc in height from the Galactic plane, and several kpc in the direction of Galactic anti-rotation (at longitude 260{deg}<=l<=280{deg}). This allows us to reliably measure the vertical density and abundance profiles of the chemically and kinematically defined 'thick' and 'thin' discs of the Galaxy. The thin disc (low-{alpha} population) exhibits a steep negative vertical metallicity gradient, at d[M/H]/dz=-0.18+/-0.01dex/kpc, which is broadly consistent with previous studies. In contrast, its vertical {alpha}-abundance profile is almost flat, with a gradient of d[{alpha}/M]/dz=0.008+/-0.002dex/kpc. The steep vertical metallicity gradient of the low-{alpha} population is in agreement with models where radial migration has a major role in the evolution of the thin disc. The thick disc (high-{alpha} population) has a weaker vertical metallicity gradient d[M/H]/dz=-0.058+/-0.003dex/kpc. The {alpha}-abundance of the thick disc is nearly constant with height, d[{alpha}/M]/dz=0.007+/-0.002dex/kpc. The negative gradient in metallicity and the small gradient in [{alpha}/M] indicate that the high-{alpha} population experienced a settling phase, but also formed prior to the onset of major Type Ia supernova enrichment. We explore the implications of the distinct {alpha}-enrichments and narrow [{alpha}/M] range of the sub-populations in the context of thick disc formation.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/525/A90
- Title:
- Thick disc vertical properties
- Short Name:
- J/A+A/525/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work investigates the properties (metallicity and kinematics) and interfaces of the Galactic thick disc as a function of height above the Galactic plane. The main aim is to study the thick disc in a place where it is the main component of the sample. We take advantage of former astrometric work in two fields of several square degrees in which accurate proper motions were measured down to V-magnitudes of 18.5 in two directions, one near the north galactic pole and the other at a galactic latitude of 46{deg} and galactic longitude near 0{deg}. Spectroscopic observations have been acquired in these two fields for a total of about 400 stars down to magnitude 18.0, at spectral resolutions of 3.5 to 6.25{AA}. The spectra have been analysed with the code ETOILE, comparing the target stellar spectra with a grid of 1400 reference stellar spectra. This comparison allowed us to derive the parameters effective temperature, gravity, [Fe/H] and absolute magnitude for each target star.
- ID:
- ivo://CDS.VizieR/J/AJ/109/1095
- Title:
- Thick Disk Chemical Abundance Distribution
- Short Name:
- J/AJ/109/1095
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a determination of the thick disk iron abundance distribution obtained from an in situ sample of F/G stars. These stars are faint, 15<=V=<18, selected on the basis of color, being a subset of the larger survey of Gilmore and Wyse designed to determine the properties of the stellar populations several kiloparsecs from the Sun. The fields studied in the present paper probe the iron abundance distribution of the stellar populations of the galaxy at 500-3000pc above the plane, at the solar Galactocentric distance. The derived chemical abundance distributions are consistent with no metallicity gradients in the thick disk over this range of vertical distance, and with an iron abundance distribution for the thick disk that has a peak at -0.7dex. The lack of a vertical gradient argues against slow, dissipational settling as a mechanism for the formation of the thick disk. The photometric and metallicity data support a turn-off of the thick disk that is comparable in age to the metal-rich globular clusters, or >=12Gyr, and are consistent with a spread to older ages.
- ID:
- ivo://CDS.VizieR/J/PAZh/38/860
- Title:
- Thin disk BV-GV Hipparcos stars within 333pc
- Short Name:
- J/PAZh/38/860
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The variations of kinematic parameters with age are considered for a sample of 15402 thin-disk O-F stars with accurate RA, DEC, proper motion, and parallax higher than 3 mas from the Hipparcos catalogue (2007A&A...474..653V) and radial velocities from the PCRV (2006PAZh...32..844G) catalogue. The ages have been calculated from the positions of the stars on the Hertzsprung-Russell diagram relative to the isochrones from the Padova database (http://stev.oapd.inaf.it/cmd) by taking into account the extinction from the previously constructed 3D analytical model (2009AstL...35..780G) and extinction coefficient RV from the 3D map of its variations (2012AstL...38...12G). Smooth, mutually reconciled variations of the velocity dispersions sigma(U), sigma(V), sigma(W), solar motion components Usun, Vsun, Wsun, Ogorodnikov-Milne model parameters, Oort constants, and vertex deviation lxy consistent with all of the extraneous results for which the stellar ages were determined have been found and presented in the table solution.dat. The velocity dispersion variations are well fitted by power laws the deviations from which are explained by the influence of predominantly radial stellar streams: Sirius, Hyades, alpha Cet/Wolf 630, and Hercules. The accuracy of determining the solar motion relative to the local standard of rest is shown to be fundamentally limited due to these variations of stellar kinematics. The deviations of our results from those of Dehnen and Binney (1998MNRAS.294..429D), the Geneva-Copenhagen survey of dwarfs (V/117), and the Besancon model of the Galaxy (2003A&A...409..523R) are explained by the use of PCRV radial velocities with corrected systematic errors.
- ID:
- ivo://CDS.VizieR/IX/16
- Title:
- Third Ariel X-Ray Catalogue (3A)
- Short Name:
- IX/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog lists the high and low latitude X-ray sources observed with the Sky Survey Instrument on board the ARIEL 5 satellite (UK 5) as published by Warwick et al. (1981MNRAS.197..865W) and McHardy et al. (1981MNRAS.197..893M). ARIEL 5 scanned the sky for 5.5yrs in the energy bands 2-18 keV with a time resolution of one orbit (100min approximately). The fields in the catalog list source name and up to three alternative names; the error box center and corners in decimal degrees; average, minimum, and maximum flux and their error; a variability code; identification; and comments.
- ID:
- ivo://nasa.heasarc/fermi3fhl
- Title:
- Third Catalog of Hard Fermi-LAT Sources (3FHL)
- Short Name:
- FERMI3FHL
- Date:
- 28 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is a catalog of sources detected above 10 GeV by the Fermi-Large Area Telescope (LAT) in the first 7 years of data using the Pass 8 event-level analysis. It contains 1558 objects characterized in the 10 GeV to 2 TeV energy range. The sensitivity and angular resolution are improved by factors of 3 and 2 relative to the previous LAT catalog at the same energies (1FHL). The vast majority of detected sources (79%) are extragalactic, including 16 sources located at very high redshift (z > 2). Nine percent of the sources are Galactic and 12% are unassociated (or associated with a source of unknown nature). The high-latitude sky and the Galactic plane are observed with an average sensitivity of 0.5% and 1% of the Crab Nebula flux above 10 GeV, respectively. The catalog includes 225 new gamma-ray sources. The substantial increase in the number of photons (more than 4 times relative to the 1FHL and 10 times to the 2FHL) also allows us to characterize spectral curvature for 32 sources and flux variability for 163 of them. Furthermore, we estimate that for the same energy flux limit of 10<sup>-12</sup> erg cm<sup>2</sup> s<sup>-1</sup>, the energy range above 10 GeV has twice as many sources as the range above 50 GeV, which confirms and quantifies the importance of lowering the energy threshold of Cherenkov telescopes as much as possible in order to increase the number of available sources. This database table was first ingested by the HEASARC in December 2017 using electronic data obtained from the Fermi Science Support Center (FSSC). That data is available at <a href="http://fermi.gsfc.nasa.gov/ssc/data/access/lat/3FHL/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/3FHL/</a>. This is a service provided by NASA HEASARC .
- 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.
22188. Third EGRET catalog (3EG)
- ID:
- ivo://CDS.VizieR/J/ApJS/123/79
- Title:
- Third EGRET catalog (3EG)
- Short Name:
- J/ApJS/123/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The third catalog of high-energy gamma-ray sources detected by the EGRET telescope on the Compton Gamma Ray Observatory (3EG) includes data from 1991 April 22 to 1995 October 3 (cycles 1, 2, 3, and 4 of the mission). In addition to including more data than the second EGRET catalog and its supplement, this catalog uses completely reprocessed data to correct a number of mostly minimal errors and problems. 14 sources (3 from the Supplement) listed in Table 6 below are not appearing in the 3EG. The 271 sources (E>100 MeV) in the catalog include the single 1991 solar flare bright enough to be detected as a source, the Large Magellanic Cloud, five pulsars, one probable radio galaxy detection (Cen A), and 66 high-confidence identifications of blazars (BL Lac objects, flat-spectrum radio quasars, or unidentified flat-spectrum radio sources). In addition, 27 lower confidence potential blazar identifications are noted. Finally, the catalog contains 170 sources not yet identified firmly with known objects, although potential identifications have been suggested for a number of those. This catalog supersedes the 2EG (Cat. <J/ApJS/101/259>) and its supplement (Cat. <J/ApJS/107/227>).
- ID:
- ivo://CDS.VizieR/J/ApJS/170/175
- Title:
- Third IBIS/ISGRI soft gamma-ray survey catalog
- Short Name:
- J/ApJS/170/175
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we report on the third soft gamma-ray source catalog obtained with the IBIS/ISGRI gamma-ray imager on board the INTEGRAL satellite. The scientific data set is based on more than 40Ms of high-quality observations performed during the first 3.5yr of Core Program and public IBIS/ISGRI observations. Compared to previous IBIS/ISGRI surveys, this catalog includes a substantially increased coverage of extragalactic fields, and comprises more than 400 high-energy sources detected in the energy range 17-100keV, including both transients and faint persistent objects that can only be revealed with longer exposure times.
- ID:
- ivo://CDS.VizieR/J/other/PBeiO/17.105
- Title:
- Third preliminary catalogue of stars
- Short Name:
- J/other/PBeiO/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On the basis of the data observed with the Photoelectric Transit Instrument, of the Beijing Astronomical Observatory during the period from 1980 through 1984, the third preliminary catalogue of stars on right ascension observed with the Photoelectric Transit Instrument (PPCP3) have been compiled. The relations between the residuals V and the magnitude M, and the spectral type S of FK4 stars are discussed. There are 411 stars in this catalogue. The mean precisions of {DELTA}alpha's is +/-2.3ms. Finally systematic corrections of PPCP3-FK4 are given.
![To the extent possible under law, the publisher has waived all copyright and related or neighboring rights to GAVO's ADQL course. For details, see the `Creative Commons CC0 1.0 Public Domain dedication <http://creativecommons.org/publicdomain/zero/1.0/>`_. Of course, you should still give proper credit when using this data as required by good scientific practice. .. image:: /static/img/cc0.png :alt: [CC0]](/registry-search/?f%5Brights_facet%5D%5B%5D=To+the+extent+possible+under+law%2C+the+publisher+has+waived+all+copyright+and+related+or+neighboring+rights+to+GAVO%27s+ADQL+course.++For+details%2C+see+the+%60Creative+Commons+CC0+1.0+Public+Domain+dedication+%3Chttp%3A%2F%2Fcreativecommons.org%2Fpublicdomain%2Fzero%2F1.0%2F%3E%60_.++Of+course%2C+you+should+still+give+proper+credit+when+using+this+data+as+required+by+good+scientific+practice.%0A%0A..+image%3A%3A+%2Fstatic%2Fimg%2Fcc0.png%0A+++%3Aalt%3A+%5BCC0%5D%0A%0A&f%5BvalidationLevel_facet%5D%5B%5D=2){kind=link}