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15451. The Fifth U.S. Naval Observatory CCD Astrograph Catalog
ID:
ivo://irsa.ipac/USNO/Catalog/UCAC5
Title:
The Fifth U.S. Naval Observatory CCD Astrograph Catalog
Short Name:
UCAC5
Date:
01 Oct 2018 20:27:21
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The US Naval Observatory (USNO) has a long history of providing accurate astrometric data for millions of stars from their own observations plus other data. The USNO CCD Astrograph Catalog (UCAC) project utiized the "redlens" 20 cm aperture astrograph in an all-sky observing program between 1997 and 2004 (CTIO in the south, NOFS in the north) with a limiting magnitude of about R = 16.5. The previous release, UCAC4, became available in 2012. The 1st Gaia data release provides proper motions for only about 2 million stars (TGAS subset of the Tycho-2 stars) in the mainly 6 to 11.5 magnitude range. Gaia DR2 which will contain proper motions of about a billion stars is scheduled for release in April 2018. In the meantime the astronomical community would benefit from proper motions of millions of stars fainter than the Tycho-2 limit, if a substantial improvement in precision and accuraccy could be made beyond what was available in the pre-Gaia era. Re-reduction of UCAC + combine with Gaia DR1 provides proper motions for over 107 million stars on the 1 to 5 mas/yr level, strongly depending on magnitude. UCAC observations (mean epoch 2001) provide positions with 10 to 70 mas precision, and about 14 years of epoch difference to Gaia DR1.
15452. The fifth U.S. Naval Observatory CCD Astrograph Catalog (UCAC5)
ID:
ivo://org.gavo.dc/ucac5/q/cone
Title:
The fifth U.S. Naval Observatory CCD Astrograph Catalog (UCAC5)
Short Name:
UCAC 5
Date:
27 Dec 2024 08:31:04
Publisher:
The GAVO DC team
Description:
New astrometric reductions of the US Naval Observatory CCD Astrograph Catalog (UCAC) all-sky observations were performed from first principles using the TGAS stars in the 8 to 11 magnitude range as reference star catalog. Significant improvements in the astrometric solutions were obtained and the UCAC5 catalog of mean positions at a mean epoch near 2001 was generated. By combining UCAC5 with Gaia DR1 data new proper motions on the Gaia coordinate system for over 107 million stars were obtained with typical accuracies of 1 to 2 mas/yr (R = 11 to 15 mag), and about 5 mas/yr at 16th mag. Proper motions of most TGAS stars are improved over their Gaia data and the precision level of TGAS proper motions is extended to many millions more, fainter stars. The database table uses actual NULLs for missing photometry, and all angular coordinates have been homogenised to degrees.
15453. The FIRST bright QSO survey
ID:
ivo://CDS.VizieR/J/AJ/112/407
Title:
The FIRST bright QSO survey
Short Name:
J/AJ/112/407
Date:
21 Oct 2021
Publisher:
CDS
Description:
The FIRST radio survey provides a new resource for constructing a large quasar sample. With source positions accurate to better than 1" and a point source sensitivity limit of 1mJy, it reaches 50 times deeper than previous radio catalogs. We report here on the results of the pilot phase for a FIRST Bright Quasar Survey (FBQS). Based on matching the radio catalog from the initial 300{deg}^2^ of FIRST coverage with the optical catalog from the Automated Plate Machine (APM) digitization of Palomar Sky Survey plates, we have defined a sample of 219 quasar candidates brighter than E=17.50. We have obtained optical spectroscopy for 151 of these and classified 25 others from the literature, yielding 69 quasars or Seyfert 1 galaxies, of which 51 are new identifications. The brightest new quasar has an E magnitude of 14.6 and z=0.91; four others are brighter than E=16. The redshifts range from z=0.12 to 3.42. Half of the detected objects are radio quiet with L_21-cm_<10^32.5^ergs/s. We use the results of this pilot survey to establish criteria for the FBQS that will produce a quasar search program which will be 70% efficient and 95% complete to a 21-cm flux density limit of 1.0mJy.
15454. The FIRST bright quasar survey. II.
ID:
ivo://CDS.VizieR/J/ApJS/126/133
Title:
The FIRST bright quasar survey. II.
Short Name:
J/ApJS/126/133
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the Very Large Array (VLA) FIRST survey and the Automated Plate Measuring Facility (APM) catalog of the Palomar Observatory Sky Survey I (POSS-I) plates as the basis for constructing a new radio-selected sample of optically bright quasars. This is the first radio-selected sample that is competitive in size with current optically selected quasar surveys. Using only two basic criteria, radio-optical positional coincidence and optical morphology, quasars and BL Lac objects can be identified with 60% selection efficiency; the efficiency increases to 70% for objects fainter than 17 mag. We show that a more sophisticated selection scheme can predict with better than 85% reliability which candidates will turn out to be quasars. This paper presents the second installment of the FIRST Bright Quasar Survey (FBQS), with a catalog of 636 quasars distributed over 2682 deg^2^. The quasar sample is characterized and all spectra are displayed.
15455. The FIRST bright quasar survey. III.
ID:
ivo://CDS.VizieR/J/ApJS/135/227
Title:
The FIRST bright quasar survey. III.
Short Name:
J/ApJS/135/227
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of an extension of the FIRST Bright Quasar Survey (FBQS) to the South Galactic cap, and to a fainter optical magnitude limit. Radio source counterparts with SERC R magnitudes brighter than 18.9 which meet the other FBQS criteria are included. We supplement this list with a modest number of additional objects to test our completeness for quasars with extended radio morphologies. The survey covers 589deg^2^ in two equatorial strips in the southern cap. We have obtained spectra for 86% of the 522 candidates and find 321 radio-selected quasars of which 264 are reported here for the first time. A comparison of this fainter sample with the FBQS sample shows the two to be generally similar. Fourteen new broad absorption line (BAL) quasars are included in this sample. When combined with the previously identified BAL quasars in our earlier papers, we can discern a break in the frequency of BAL quasars with radio loudness, namely that the relative number of high-ionization BAL quasars drops by a factor of 4 for quasars with a radio-loudness parameter R*>100.
15456. The First CEMP star in the Sculptor dSph
ID:
ivo://CDS.VizieR/J/A+A/574/A129
Title:
The First CEMP star in the Sculptor dSph
Short Name:
J/A+A/574/A129
Date:
04 Feb 2022 11:54:02
Publisher:
CDS
Description:
he origin of carbon-enhanced metal-poor (CEMP) stars and their possible connection with the chemical elements produced by the first stellar generation is still highly debated. In contrast to the Galactic halo, not many CEMP stars have been found in the dwarf spheroidal galaxies around the Milky Way. Here we present detailed abundances from ESO VLT/UVES high-resolution spectroscopy for ET0097, the first CEMP star found in the Sculptor dwarf spheroidal, which is one of the best studied dwarf galaxies in the Local Group. This star has [Fe/H]=-2.03+/-0.10, [C/Fe]=0.51+/-0.10 and [N/Fe]=1.18+/-0.20, which is the first nitrogen measurement in this galaxy. The traditional definition of CEMP stars is [C/Fe]>=0.70, but taking into account that this luminous red giant branch star has undergone mixing, it was intrinsically less nitrogen enhanced and more carbon-rich when it was formed, and so it falls under the definition of CEMP stars, as proposed by Aoki et al. (2007ApJ...655..492A, Cat. J/ApJ/655/492) to account for this effect.
15457. The first Fermi-LAT >10GeV catalog (1FHL)
ID:
ivo://CDS.VizieR/J/ApJS/209/34
Title:
The first Fermi-LAT >10GeV catalog (1FHL)
Short Name:
J/ApJS/209/34
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of {gamma}-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during the first 3yr of the Fermi Gamma-ray Space Telescope mission. The first Fermi-LAT catalog of >10GeV sources (1FHL) has 514 sources. For each source we present location, spectrum, a measure of variability, and associations with cataloged sources at other wavelengths. We found that 449 (87%) could be associated with known sources, of which 393 (76% of the 1FHL sources) are active galactic nuclei. Of the 27 sources associated with known pulsars, we find 20 (12) to have significant pulsations in the range >10 GeV (>25 GeV). In this work we also report that, at energies above 10 GeV, unresolved sources account for 27%+/-8% of the isotropic {gamma}-ray background, while the unresolved Galactic population contributes only at the few percent level to the Galactic diffuse background. We also highlight the subset of the 1FHL sources that are best candidates for detection at energies above 50-100 GeV with current and future ground-based {gamma}-ray observatories.
15458. The first Fermi LAT SNR catalog (1SC)
ID:
ivo://CDS.VizieR/J/ApJS/224/8
Title:
The first Fermi LAT SNR catalog (1SC)
Short Name:
J/ApJS/224/8
Date:
21 Oct 2021
Publisher:
CDS
Description:
To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.
15459. The FIRST-2MASS red QSO survey. II.
ID:
ivo://CDS.VizieR/J/ApJ/698/1095
Title:
The FIRST-2MASS red QSO survey. II.
Short Name:
J/ApJ/698/1095
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results on a survey to find extremely dust-reddened Type 1 quasars. Combining the FIRST radio survey, the 2MASS Infrared Survey and the Sloan Digital Sky Survey, we have selected a candidate list of 122 potential red quasars. With more than 80% spectroscopically identified objects, well over 50% are classified as dust-reddened Type 1 quasars, whose reddenings (E(B-V)) range from approximately 0.1 to 1.5mag. They lie well off the color selection windows usually used to detect quasars and many fall within the stellar locus, which would have made it impossible to find these objects with traditional color selection techniques. The reddenings found are much more consistent with obscuration happening in the host galaxy rather than stemming from the dust torus. We find an unusually high fraction of broad absorption line (BAL) quasars at high redshift, all but one of them belonging to the low-ionization BAL (LoBAL) class and many also showing absorption in the metastable FeII line (FeLoBAL). The discovery of further examples of dust-reddened LoBAL quasars provides more support for the hypothesis that BAL quasars (at least LoBAL quasars) represent an early stage in the lifetime of the quasar. The fact that we see such a high fraction of BALs could indicate that the quasar is in a young phase in which quasar feedback from the BAL winds is suppressing star formation in the host galaxy.
15460. The FIRST sample of ultraluminous IR galaxies
ID:
ivo://CDS.VizieR/J/ApJS/131/185
Title:
The FIRST sample of ultraluminous IR galaxies
Short Name:
J/ApJS/131/185
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new sample of distant ultraluminous infrared galaxies. The sample was selected from a positional cross-correlation of the IRAS Faint Source Catalog (Cat. <II/156>) with the FIRST database. Objects from this set were selected for spectroscopy by virtue of following the well-known star-forming galaxy correlation between 1.4 GHz and 60 {mu}m flux, and by being optically faint on the POSS. Optical identification and spectroscopy were obtained for 108 targets at the Lick Observatory 3 m telescope.

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