Search

Start Over Capability Type Simple Cone Search
931. Archival Keck HIRES spectra analyzed with The Cannon
ID:
ivo://CDS.VizieR/J/ApJ/898/119
Title:
Archival Keck HIRES spectra analyzed with The Cannon
Short Name:
J/ApJ/898/119
Date:
15 Dec 2021 00:08:08
Publisher:
CDS
Description:
To accurately interpret the observed properties of exoplanets, it is necessary to first obtain a detailed understanding of host star properties. However, physical models that analyze stellar properties on a per-star basis can become computationally intractable for sufficiently large samples. Furthermore, these models are limited by the wavelength coverage of available spectra. We combine previously derived spectral properties from the Spectroscopic Properties of Cool Stars (SPOCS) catalog with generative modeling using The Cannon to produce a model capable of deriving stellar parameters (logg, Teff, and vsini) and 15 elemental abundances (C, N, O, Na, Mg, Al, Si, Ca, Ti, V, Cr, Mn, Fe, Ni, and Y) for stellar spectra observed with Keck Observatory's High Resolution Echelle Spectrometer (HIRES). We demonstrate the high accuracy and precision of our model, which takes just ~3s to classify each star, through cross-validation with pre-labeled spectra from the SPOCS sample. Our trained model, which takes continuum-normalized template spectra as its inputs, is publicly available at http://github.com/malenarice/keckspec. Finally, we interpolate our spectra and employ the same modeling scheme to recover labels for 477 stars using archival stellar spectra obtained prior to Keck's 2004 detector upgrade, demonstrating that our interpolated model can successfully predict stellar labels for different spectrographs that have (1) sufficiently similar systematics and (2) a wavelength range that substantially overlaps with that of the post-2004 HIRES spectra.
932. Archive of Chandra Cluster Entropy Profile Tables (ACCEPT) Catalog
ID:
ivo://nasa.heasarc/acceptcat
Title:
Archive of Chandra Cluster Entropy Profile Tables (ACCEPT) Catalog
Short Name:
ACCEPTCAT
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table, the Archive of Chandra Cluster Entropy Profile Tables (ACCEPT) Catalog, contains the radial entropy profiles of the intracluster medium (ICM) for a collection of 239 clusters taken from the Chandra X-ray Observatory's Data Archive. Entropy is of great interest because it controls ICM global properties and records the thermal history of a cluster. The authors find that most ICM entropy profiles are well fitted by a model which is a power law at large radii and approaches a constant value at small radii: K(r) = K<sub>0</sub> + K<sub>100</sub> (r/100 kpc)<sup>alpha</sup>, where K<sub>0</sub> quantifies the typical excess of core entropy above the best-fitting power law found at larger radii. The authors also show that the K<sub>0</sub> distributions of both the full archival sample and the primary Highest X-Ray Flux Galaxy Cluster Sample of Reiprich (2001, Ph.D. thesis) are bimodal with a distinct gap between K<sub>0</sub> ~ 30 - 50 keV cm<sup>2</sup> and population peaks at K<sub>0</sub> ~ 15 keV cm<sup>2</sup> and K<sub>0</sub> ~ 150 keV cm<sup>2</sup>. The effects of point-spread function smearing and angular resolution on best-fit K<sub>0</sub> values are investigated using mock Chandra observations and degraded entropy profiles, respectively. The authors find that neither of these effects is sufficient to explain the entropy-profile flattening they measure at small radii. The influence of profile curvature and the number of radial bins on the best-fit K<sub>0</sub> is also considered, and they find no indication that K<sub>0</sub> is significantly impacted by either. All data and results associated with this work are publicly available via the project web site <a href="http://www.pa.msu.edu/astro/MC2/accept/">http://www.pa.msu.edu/astro/MC2/accept/</a>. The sample is collected from observations taken with the Chandra X-ray Observatory and which were publicly available in the CDA (Chandra Data Archive) as of 2008 August. This table was created by the HEASARC in January 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/182/12">CDS Catalog J/ApJS/182/12</a> files table1.dat and table5.dat. This is a service provided by NASA HEASARC .
933. Arcsecond positions of UGC galaxies
ID:
ivo://CDS.VizieR/J/ApJS/125/409
Title:
Arcsecond positions of UGC galaxies
Short Name:
J/ApJS/125/409
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present accurate B1950 and J2000 positions for all confirmed galaxies in the Uppsala General Catalog (UGC, Cat. <VII/26>). The positions were measured visually from Digitized Sky Survey images with rms uncertainties {sigma}<=[(1.2")^2^+({theta}/100)^2^]^1/2^, where is the major-axis diameter. We compared each galaxy measured with the original UGC description to ensure high reliability. The full position list is available in the electronic version only. the major-axis diameter. We compared each galaxy measured with the original UGC description to ensure high reliability. The full position list is available in the electronic version only.
934. Arecibo 21cm obs. of sources in 5 GMC regions
ID:
ivo://CDS.VizieR/J/ApJ/880/141
Title:
Arecibo 21cm obs. of sources in 5 GMC regions
Short Name:
J/ApJ/880/141
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report Arecibo 21cm absorption-emission observations to characterize the physical properties of neutral hydrogen (HI) in the proximity of five giant molecular clouds (GMCs): Taurus, California, Rosette, Mon OB1, and NGC 2264. Strong HI absorption was detected toward all 79 background-continuum sources in the ~60x20 square degree region. Gaussian decompositions were performed to estimate temperatures, optical depths, and column densities of the cold and warm neutral medium (CNM and WNM). The properties of individual CNM components are similar to those previously observed along random Galactic sightlines and in the vicinity of molecular clouds, suggesting a universality of cold HI properties. The CNM spin temperature (Ts) histogram peaks at ~50K. The turbulent Mach numbers of CNM components vary widely, with a typical value of ~4, indicating that their motions are supersonic. About 60% of the total HI gas is WNM, and nearly 40% of the WNM lies in thermally unstable regime 500-5000K. The observed CNM fraction is higher around GMCs than in diffuse regions, and increases with increasing column density (N_HI_) to a maximum of ~75%. On average, the optically thin approximation (N_HI_^*^) underestimates the total column density by ~21%, but we find large regional differences in the relationship between N_HI_ and the required correction factor, f=N_HI_/N_HI_^*^. We examine two different methods (linear fit of f versus log_10_(N_HI_^*^) and uniform Ts) to correct for opacity effects using emission data from the GALFA-HI survey. We prefer the uniform Ts method because the linear relationship does not produce convincing fits for all subregions.
935. Arecibo Dual-Beam Survey
ID:
ivo://CDS.VizieR/J/ApJS/130/177
Title:
Arecibo Dual-Beam Survey
Short Name:
J/ApJS/130/177
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Arecibo Dual-Beam Survey is a "blind" 21 cm search for galaxies covering ~430deg^2^ of sky. We present the data from the detection survey as well as from the follow-up observations to confirm detections and improve positions and flux measurements. We find 265 galaxies, many of which are extremely low surface brightness. Some of these previously uncatalogued galaxies lie within the zone of avoidance, where they are obscured by the gas and dust in our Galaxy. Eighty-one of these sources are not previously catalogued optically, and there are 11 galaxies that have no associated optical counterpart or are only tentatively associated with faint wisps of nebulosity on the Digitized Sky Survey images. We discuss the properties of the survey, and in particular we make direct determinations of the completeness and reliability of the sample. The behavior of the completeness and its dependencies is essential for determining the H I mass function. We leave the discussion of the mass function for a later paper, but do note that we find many low surface brightness galaxies and seven sources with M_HI_<10^8^M_{sun}_.
936. Arecibo Legacy Fast Alfa Survey (ALFALFA) VIII.
ID:
ivo://CDS.VizieR/J/ApJS/183/214
Title:
Arecibo Legacy Fast Alfa Survey (ALFALFA) VIII.
Short Name:
J/ApJS/183/214
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a fourth catalog of HI sources from the Arecibo Legacy Fast ALFA (ALFALFA) Survey. We report 541 detections over 136deg^2^, within the region of the sky having 22h<RA<03h and 24<DE<26{deg}. This complements a previous catalog in the region 26<DE<28{deg}. We present here the detections falling into three classes: (1) extragalactic sources with signal-to-noise ratio (S/N)>6.5, where the reliability of the catalog is better than 95%; (2) extragalactic sources 5.0<S/N<6.5 and a previously measured optical redshift that corroborates our detection; or (3) High Velocity Clouds (HVCs), or subcomponents of such clouds, in the periphery of the Milky Way. Of the 541 objects presented here, 90 are associated with HVCs, while the remaining 451 are identified as extragalactic objects. Optical counterparts have been matched with all but one of the extragalactic objects.
937. Arecibo legacy fast ALFA survey III.
ID:
ivo://CDS.VizieR/J/AJ/133/2569
Title:
Arecibo legacy fast ALFA survey III.
Short Name:
J/AJ/133/2569
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first installment of HI sources extracted from the Arecibo Legacy Fast ALFA (ALFALFA) extragalactic survey, initiated in 2005. Sources have been extracted from three-dimensional spectral data cubes exploiting a matched filtering technique and then examined interactively to yield global HI parameters. A total of 730 HI detections are cataloged within the solid angle 11h44<RA(J2000.0)<14h00 and +12{deg}<DE(J2000.0)<+16{deg} and redshift range -1600km/s<cz<18000km/s. In comparison, the HI Parkes All-Sky Survey (HIPASS, Meyer et al. 2004, Cat. VIII/73) detected 40 HI signals in the same region. Optical counterparts are assigned via examination of digital optical imaging databases.
938. Arecibo Legacy Fast ALFA Survey. IX.
ID:
ivo://CDS.VizieR/J/AJ/138/338
Title:
Arecibo Legacy Fast ALFA Survey. IX.
Short Name:
J/AJ/138/338
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the catalog of HI sources extracted from the ongoing Arecibo Legacy Fast ALFA (ALFALFA) extragalactic HI line survey, found within the sky region bounded by 9:36<RA<11:36 and +08<DE<+12. The HI catalog presented here for this 118deg^2^ region is combined with the ones derived from surrounding regions also covered by the ALFALFA survey to examine the large-scale structure in the complex Leo region. Because of the combination of wide sky coverage and superior sensitivity, spatial and spectral resolution, the ALFALFA HI catalog of the Leo region improves significantly on the numbers of low HI mass sources as compared with those found in previous HI surveys.
939. Arecibo legacy fast ALFA survey V.
ID:
ivo://CDS.VizieR/J/AJ/135/588
Title:
Arecibo legacy fast ALFA survey V.
Short Name:
J/AJ/135/588
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a second catalog of HI sources detected in the Arecibo Legacy Fast ALFA Survey. We report 488 detections over 135deg^2^, within the region of the sky having 22<RA<03 and +26<DE<+28. We present here the detections that have either (a) S/N>6.5, where the reliability of the catalog is better than 95% or (b) 5.0<S/N<6.5 and a previously measured redshift that corroborates our detection. Of the 488 objects presented here, 49 are high-velocity clouds or clumps thereof with negative heliocentric recession velocities. These clouds are mostly very compact and isolated, while some of them are associated with large features such as Wright's Cloud or the northern extension of the Magellanic Stream. The remaining 439 candidate detections are identified as extragalactic objects and have all been matched with optical counterparts. Five of the six galaxies detected with M_HI_<10^7.5^ solMass are satellites of either the NGC672/IC1727 nearby galaxy pair or their neighboring dwarf irregular galaxy NGC784. The data of this catalog release include a slice through the Pisces-Perseus foreground void, a large nearby underdensity of galaxies. We report no detections within the void, where our catalog is complete for systems with HI masses of 10^8^M_{sun}_.
940. Arecibo legacy fast ALFA survey. VI.
ID:
ivo://CDS.VizieR/J/AJ/136/713
Title:
Arecibo legacy fast ALFA survey. VI.
Short Name:
J/AJ/136/713
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the third installment of HI sources extracted from the Arecibo Legacy Fast ALFA extragalactic survey. This data set continues the work of the Virgo ALFALFA catalog. The catalogs and spectra published here consist of data obtained during the 2005 and 2006 observing sessions of the survey. The catalog consists of 578 HI detections within the range 11h36m<RA(J2000)<13h52m and +08{deg}<DE(J2000)<+12{deg}, and cz_{sun}_<18000km/s. The catalog entries are matched with optical counterparts where possible through the examination of digitized optical images. The catalog detections can be classified into three categories: (a) detections of high reliability with a signal-to-noise ratio (S/N)>6.5; (b) high-velocity clouds in the Milky Way or its periphery; and (c) signals of lower S/N which coincide spatially with an optical object and known redshift. 75% of the sources are newly published HI detections. Of particular note is a complex of HI clouds projected between M87 and M49 that do not coincide with any optical counterparts. Candidate objects without optical counterparts are few. Position corrections for telescope pointing errors are applied to the data set by comparing the ALFALFA continuum centroid with those cataloged in the NRAO VLA Sky Survey (NVSS, Cat. VIII/65). The uncorrected positional accuracy averages 27"(21" median) for all sources with S/N>6.5 and is of order ~21"(16" median) for signals with S/N>12. Uncertainties in distances toward the Virgo cluster can affect the calculated HI mass distribution.

Limit your search

more »

more »

more »

more »

more »

more »