Search

Start Over Capability Type Simple Cone Search
15831. The YSO population of LDN 1340 in infrared
ID:
ivo://CDS.VizieR/J/ApJS/224/22
Title:
The YSO population of LDN 1340 in infrared
Short Name:
J/ApJS/224/22
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results of an infrared study of the molecular cloud Lynds 1340, forming three groups of low- and intermediate-mass stars. Our goals are to identify and characterize the young stellar population of the cloud, study the relationships between the properties of the cloud and the emergent stellar groups, and integrate L1340 into the picture of the star-forming activity of our Galactic environment. We selected candidate young stellar objects (YSOs) from the Spitzer and WISE databases using various published color criteria and classified them based on the slope of the spectral energy distribution (SED). We identified 170 Class II, 27 flat SED, and 45 Class 0/I sources. High angular resolution near-infrared observations of the RNO 7 cluster, embedded in L1340, revealed eight new young stars of near-infrared excess. The surface density distribution of YSOs shows three groups, associated with the three major molecular clumps of L1340, each consisting of <~100 members, including both pre-main-sequence stars and embedded protostars. New Herbig-Haro objects were identified in the Spitzer images. Our results demonstrate that L1340 is a prolific star-forming region of our Galactic environment in which several specific properties of the intermediate-mass mode of star formation can be studied in detail.
15832. The zCOSMOS 10k-bright spectroscopic sample
ID:
ivo://CDS.VizieR/J/ApJS/184/218
Title:
The zCOSMOS 10k-bright spectroscopic sample
Short Name:
J/ApJS/184/218
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present spectroscopic redshifts of a large sample of galaxies with I_AB_<22.5 in the COSMOS field, measured from spectra of 10644 objects that have been obtained in the first two years of observations in the zCOSMOS-bright redshift survey. These include a statistically complete subset of 10109 objects. The average accuracy of individual redshifts is 110km/s, independent of redshift. The reliability of individual redshifts is described by a Confidence Class that has been empirically calibrated through repeat spectroscopic observations of over 600 galaxies. There is very good agreement between spectroscopic and photometric redshifts for the most secure Confidence Classes. For the less secure Confidence Classes, there is a good correspondence between the fraction of objects with a consistent photometric redshift and the spectroscopic repeatability, suggesting that the photometric redshifts can be used to indicate which of the less secure spectroscopic redshifts are likely right and which are probably wrong, and to give an indication of the nature of objects for which we failed to determine a redshift. Using this approach, we can construct a spectroscopic sample that is 99% reliable and which is 88% complete in the sample as a whole, and 95% complete in the redshift range 0.5<z<0.8. The luminosity and mass completeness levels of the zCOSMOS-bright sample of galaxies is also discussed.
15833. The Zelenchuk Surveys
ID:
ivo://CDS.VizieR/VIII/49
Title:
The Zelenchuk Surveys
Short Name:
VIII/49
Date:
21 Oct 2021
Publisher:
CDS
Description:
The main catalog contains positions and flux densities for 8511 sources detected in the Zelenchuk 3.9 GHz Survey with declinations between 0 and 14 degrees. The survey was originally published in Amirkhanyan et al. 1989, MIR Publ., Moscow, and contained 8511 sources. The machine version has been cleaned from a few spurious sources by the authors. The angular resolution is (RA x DEC) 70"/cos(decl) x 50'. The survey is 95 percent complete to the limiting flux density 50 mJy, except near the boundaries of the declination zone. A supplementary catalogue of 2946 radio sources observed during Zelenchuk survey at 3.9 GHz in the flux density from 40 to 50 mJy within the declination range 0-14 degrees are presented. ratan is the first results of the deep search survey over a portion of the celestial sphere with the radio telescope RATAN-600 at several cm-wavelengths. The catalogue contains 691 radio sources at 3.9 GHz. Fluxes at the frequencies 3.9, 4.8, 7.5 and 11.2 GHz have been measured for the complete sample of the radio sources from the Zelenchuk survey. The sample contains all sources with S > 200 mJy in the 4-6 degree declination range.
15834. 12th General Catalogue of MK Spectral Classification
ID:
ivo://CDS.VizieR/III/223
Title:
12th General Catalogue of MK Spectral Classification
Short Name:
III/223
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the twelfth in a series of catalogs of MK spectral types and UBV photometry issued from Dearborn Observatory. It is based on an extensive search of literature published up to early 1995. Each catalog is essentially self-contained, with its separate selection of stars listed in order of increasing right ascension. Some classifications (indicated between parentheses) are inferred from photometric or astrometric considerations. The preferred identification is from the Henry Draper Catalog or the General Catalog of Variable Stars, with a Durchmusterung or other alternative as space permits.
15835. 14th General Catalogue of MK Spectral Classification
ID:
ivo://CDS.VizieR/III/222
Title:
14th General Catalogue of MK Spectral Classification
Short Name:
III/222
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the fourteenth in a series of catalogs of MK spectral types and UBV photometry issued from Dearborn Observatory. It is based on an extensive search of the literature published from ~1997 to 1999. Each catalog is essentially self-contained, with its separate selection of stars listed in order of increasing right ascension. Some classifications (indicated between parentheses) are inferred from photometric or astrometric considerations. The preferred identification is from the Henry Draper Catalog or the General Catalog of Variable Stars, with a Durchmusterung or other alternative as space permits.
15836. 13th General Catalogue of MK Spectral Classification
ID:
ivo://CDS.VizieR/III/206
Title:
13th General Catalogue of MK Spectral Classification
Short Name:
III/206
Date:
21 Oct 2021
Publisher:
CDS
Description:
A file of MK spectral types and UBV photometry maintained at Dearborn Observatory is presented here. It is based on an extensive literature search. The annex files (various clusters and associations, and SMC) are from the revised 12th catalogue.
15837. Thick disc probability of GALAH stars
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.
15838. Thick disc vertical properties
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.
15839. Thick Disk Chemical Abundance Distribution
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.
15840. Thin disk BV-GV Hipparcos stars within 333pc
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.

Limit your search

more »

more »

more »

more »

more »

more »