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17371. White dwarfs in 47 Tuc (NGC 104) with HST
ID:
ivo://CDS.VizieR/J/AJ/143/50
Title:
White dwarfs in 47 Tuc (NGC 104) with HST
Short Name:
J/AJ/143/50
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new distance determination to the Galactic globular cluster 47 Tucanae (47 Tuc, NGC 104) by fitting the spectral energy distributions of its white dwarfs (WDs) to pure hydrogen atmosphere WD models. Our photometric data set is obtained from a 121-orbit Hubble Space Telescope program using the Wide Field Camera 3 UVIS/IR channels, capturing F390W, F606W, F110W, and F160W images. These images cover more than 60 arcmin^2^ and extend over a radial range of 5-13.7arcmin (6.5-17.9pc) within the globular cluster. Using a likelihood analysis, we obtain a best-fitting unreddened distance modulus of (m-M)_o_=13.36+/-0.02+/-0.06 corresponding to a distance of 4.69+/-0.04+/-0.13kpc, where the first error is random and the second is systematic. We also search the WD photometry for infrared excess in the F160W filter, indicative of low-mass companions, and find no convincing cases within our sample.
17372. White dwarfs with cool companions
ID:
ivo://CDS.VizieR/J/ApJ/586/1356
Title:
White dwarfs with cool companions
Short Name:
J/ApJ/586/1356
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present near-infrared (IR) magnitudes for all white dwarfs (selected from the catalog of McCook & Sion, 1999, See Cat. <III/235>) contained in the Two Micron All-Sky Survey second incremental data release (2MASS 2IDR, Cat. <II/241>). We show that the near-IR color-color diagram is an effective means of identifying candidate binary stars containing a WD and a low-mass, main-sequence star. The loci of single WDs and WD+red dwarf binaries occupy distinct regions of the near-IR color-color diagram. We recovered all known unresolved WD+red dwarf binaries located in the 2IDR sky coverage and also identified as many new candidate binaries (47 new candidates out of 95 total). Using observational near-IR data for WDs and M-L dwarfs, we have compared a sample of simulated WD+red dwarf binaries with our 2MASS data. The colors of the simulated binaries are dominated by the low-mass companion through the late M to early L spectral types. As the spectral type of the companion becomes progressively later, however, the colors of unresolved binaries become progressively bluer. Binaries containing the lowest mass companions will be difficult to distinguish from single WDs solely on the basis of their near-IR colors.
17373. White dwarfs within 25pc of the Sun
ID:
ivo://CDS.VizieR/J/AJ/147/129
Title:
White dwarfs within 25pc of the Sun
Short Name:
J/AJ/147/129
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the fractional distribution of spectroscopic subtypes, range and distribution of surface temperatures, and kinematical properties of the white dwarfs (WDs) within 25pc of the Sun. There is no convincing evidence of halo WDs in the total 25pc sample of 224 WDs. There is also little to suggest the presence of genuine thick disk subcomponent members within 25pc. It appears that the entire 25pc sample likely belongs to the thin disk. We also find no significant kinematic differences with respect to spectroscopic subtypes. The total DA to non-DA ratio of the 25pc sample is 1.8, a manifestation of deepening envelope convection, which transforms DA stars with sufficiently thin H surface layers into non-DAs. We compare this ratio with the results of other studies. We find that at least 11% of the WDs within 25pc of the Sun (the DAZ and DZ stars) have photospheric metals that likely originate from accretion of circumstellar material (debris disks) around them. If this interpretation is correct, then it suggests the possibility that a similar percentage have planets, asteroid-like bodies, or debris disks orbiting them. Our volume-limited sample reveals a pileup of DC WDs at the well-known cutoff in DQ WDs at T_eff_~6000K. Mindful of small number statistics, we speculate on its possible evolutionary significance. We find that the incidence of magnetic WDs in the 25pc sample is at least 8% in our volume-limited sample, dominated by cool WDs. We derive approximate formation rates of DB and DQ degenerates and present a preliminary test of the evolutionary scenario that all cooling DB stars become DQ WDs via helium convective dredge-up with the diffusion tail of carbon extending upward from their cores.
17374. White-light flares on close binaries from Kepler
ID:
ivo://CDS.VizieR/J/ApJS/224/37
Title:
White-light flares on close binaries from Kepler
Short Name:
J/ApJS/224/37
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on Kepler data, we present the results of a search for white light flares on 1049 close binaries. We identify 234 flare binaries, of which 6818 flares are detected. We compare the flare-binary fraction in different binary morphologies ("detachedness"). The result shows that the fractions in over-contact and ellipsoidal binaries are approximately 10%-20% lower than those in detached and semi-detached systems. We calculate the binary flare activity level (AL) of all the flare binaries, and discuss its variations along the orbital period (P_orb_) and rotation period (P_rot_, calculated for only detached binaries). We find that the AL increases with decreasing P_orb_ or P_rot_, up to the critical values at P_orb_~3 days or P_rot_~1.5 days, and thereafter the AL starts decreasing no matter how fast the stars rotate. We examine the flaring rate as a function of orbital phase in two eclipsing binaries on which a large number of flares are detected. It appears that there is no correlation between flaring rate and orbital phase in these two binaries. In contrast, when we examine the function with 203 flares on 20 non-eclipse ellipsoidal binaries, bimodal distribution of amplitude-weighted flare numbers shows up at orbital phases 0.25 and 0.75. Such variation could be larger than what is expected from the cross section modification.
17375. White-light flares on cool stars from Kepler
ID:
ivo://CDS.VizieR/J/AJ/141/50
Title:
White-light flares on cool stars from Kepler
Short Name:
J/AJ/141/50
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a search for white-light flares on ~23000 cool dwarfs in the Kepler Quarter 1 long cadence data. We have identified 373 flaring stars, some of which flare multiple times during the observation period. We calculate relative flare energies, flare rates, and durations and compare these with the quiescent photometric variability of our sample.
17376. W3(H2O/OH) continuum & line data cubes at 1.3mm
ID:
ivo://CDS.VizieR/J/A+A/618/A46
Title:
W3(H2O/OH) continuum & line data cubes at 1.3mm
Short Name:
J/A+A/618/A46
Date:
21 Oct 2021
Publisher:
CDS
Description:
The fragmentation mode of high-mass molecular clumps and the properties of the central rotating structures surrounding the most luminous objects have yet to be comprehensively characterised. We study the fragmentation and kinematics of the high-mass star-forming region W3(H_2_O), as part of the IRAM NOrthern Extended Millimeter Array (NOEMA) large programme CORE. Using the IRAM NOEMA and the IRAM 30m telescope, the CORE survey has obtained high-resolution observations of 20 well-known highly luminous star-forming regions in the 1.37 mm wavelength regime in both line and dust continuum emission. We present the spectral line set-up of the CORE survey and a case study for W3(H_2_O). At ~0.35" (700AU at 2.0kpc) resolution, the W3(H_2_O) clump fragments into two cores (west and east), separated by ~2300AU. Velocity shifts of a few km/s are observed in the dense-gas tracer, CH_3_CN, across both cores, consistent with rotation and perpendicular to the directions of two bipolar outflows, one emanating from each core. The kinematics of the rotating structure about W3(H_2_O) W shows signs of differential rotation of material, possibly in a disk-like object. The observed rotational signature around W3(H_2_O) E may be due to a disk-like object, an unresolved binary (or multiple) system, or a combination of both. We fit the emission of CH_3_CN (12K-11K) K=4-6 and derive a gas temperature map with a median temperature of ~165K across W3(H_2_O). We create a Toomre Q map to study the stability of the rotating structures against gravitational instability. The rotating structures appear to be Toomre unstable close to their outer boundaries, with a possibility of further fragmentation in the differentially rotating core, W3(H_2_O) W. Rapid cooling in the Toomre unstable regions supports the fragmentation scenario. Combining millimetre dust continuum and spectral line data toward the famous high-mass star-forming region W3(H_2_O), we identify core fragmentation on large scales, and indications for possible disk fragmentation on smaller spatial scales.
17377. 1WHSP blazar candidates catalog
ID:
ivo://bsdc.icranet.org/whsp/q/cone
Title:
1WHSP blazar candidates catalog
Short Name:
whsp cone
Date:
21 Dec 2016 00:42:39
Publisher:
BSDC
Description:
The catalog 1WHSP is the result of a multi-frequency selection for blazars like SED, further filtered using IR-radio and IR-X-ray flux-ratios. The sample assembled contains almost 992 sources of HSP blazars, of which 425 are previously known blazars, 151 new identifications and 416 blazar candidates. On the very high energy trend, 299 are confirmed GeV gamma-ray photons emitters and 36 have already been detected in the TeV band.
17378. 2WHSP Catalog of High Synchrotron Peaked Blazars and Candidates
ID:
ivo://nasa.heasarc/wisehspcat
Title:
2WHSP Catalog of High Synchrotron Peaked Blazars and Candidates
Short Name:
WISEHSPCAT
Date:
28 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
High Synchrotron Peaked blazars (HSPs) dominate the gamma-ray sky at energies larger than a few GeV, however only a few hundred blazars of this type have been catalogued so far. In this paper, the authors present the 2WHSP sample, the largest and most complete list of HSP blazars available to date, which is an expansion of the 1WHSP catalog (Arsioli et al. 2015, A&amp;A, 579, A34) of gamma-ray source candidates away from the Galactic Plane. They cross-matched a number of multi-wavelength surveys (in the radio, infrared and X-ray bands) and applied selection criteria based on the radio to IR, and IR to X-ray spectral slopes. To ensure the selection of genuine HSPs, the authors examined the spectral energy distribution (SED) of each candidate and estimated the peak frequency of its synchrotron emission (nu&lt;sub&gt;peak&lt;/sub&gt;) using the Agenzia Spaziale Italiana Science Data Center (ASDC) SED tool, including only sources with nu&lt;sub&gt;peak&lt;/sub&gt; &gt; 10&lt;sup&gt;15&lt;/sup&gt; Hz (equivalent to nu&lt;sub&gt;peak&lt;/sub&gt; &gt; 4 eV). The authors have assembled the largest and most complete catalog of HSP blazars to date, which includes 1691 sources. A number of population properties, such as infrared colors, synchrotron peak, redshift distributions, and gamma-ray spectral properties, have been used to characterize the sample and maximize completeness. The authors also derived the radio log N - log S distribution. This catalog has already been used to provide seeds to discover new very high energy objects within Fermi-LAT data and to look for the counterparts of neutrino and ultra-high energy cosmic ray sources, showing its potential for the identification of promising high-energy gamma-ray sources and multi-messenger targets. This table comprises the 2WHSP catalog, a multi-frequency catalog of HSP. It contains 1691 sources, 288 of which are newly identified HSPs, 540 are previously known HSPs, 814 are HSP candidates, 45 are HSP blazars taken from the 2FHL catalog, and 4 from TeVCat (&lt;a href="http://tevcat.uchicago.edu"&gt;http://tevcat.uchicago.edu&lt;/a&gt;). This table was created by the HEASARC in February 2017 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/598/A17"&gt;CDS Catalog J/A+A/598/A17&lt;/a&gt; file 2whsp.dat. This is a service provided by NASA HEASARC .
17379. 1WHSP: VHE {gamma}-ray blazar candidates
ID:
ivo://CDS.VizieR/J/A+A/579/A34
Title:
1WHSP: VHE {gamma}-ray blazar candidates
Short Name:
J/A+A/579/A34
Date:
21 Oct 2021
Publisher:
CDS
Description:
Blazars are the dominant type of extragalactic sources at microwave and at {gamma}-ray energies. In the most energetic part of the electromagnetic spectrum (E>~100GeV) a high fraction of high Galactic latitude sources are blazars of the high synchrotron peaked (HSP) type, that is BL Lac objects with synchrotron power peaking in the UV or in the X-ray band. Building new large samples of HSP blazars is key to understand the properties of jets under extreme conditions, and to study the demographics and the peculiar cosmological evolution of these sources. High synchrotron peaked blazars are remarkably rare, with only a few hundreds of them expected to be above the sensitivity limits of currently available surveys, some of which include hundreds of millions of sources. To find these very uncommon objects, we have devised a method that combines ALLWISE survey data with multi-frequency selection criteria. The sample was defined starting from a primary list of infrared colour-colour selected sources from the ALLWISE all sky survey database, and applying further restrictions on IR-radio and IR-X-ray flux ratios. Using a polynomial fit to the multi-frequency data (radio to X-ray), we estimated synchrotron peak frequencies and fluxes of each object.
17380. Wide Angle ROSAT Pointed Survey, First Phase (WARPS-I)
ID:
ivo://nasa.heasarc/warps
Title:
Wide Angle ROSAT Pointed Survey, First Phase (WARPS-I)
Short Name:
ROSAT/WARPS
Date:
28 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
The Wide Angle ROSAT Pointed Survey, First Phase (WARPS-I) table is a catalog which contains optical identifications for objects found in a serendipitous survey of relatively deep, pointed ROSAT observations for clusters of galaxies. The X-ray source detection algorithm used by WARPS is Voronoi Tessellation and Percolation (VTP), a technique which is equally sensitive to point sources and to extended sources of low surface brightness. WARPS-I is based on the central regions of 86 ROSAT PSPC fields, covering an area of 16.2 square degrees. The X-ray source screening and optical identification process for WARPS-I yielded 34 clusters at 0.06&lt;z&lt;0.75. Twenty-two of these clusters form a complete, statistically well-defined sample drawn from 75 of these 86 fields, covering an area of 14.1 square degrees, with a flux limit of F(0.5-2.0keV) = 6.5x10&lt;sup&gt;-14&lt;/sup&gt; erg/cm&lt;sup&gt;2&lt;/sup&gt;/s. This sample can be used to study the properties and evolution of the gas, galaxy and dark matter content of clusters and to constrain cosmological parameters. This online catalog was created by the HEASARC in May 2003 based on machine-readable versions of tables 2, 3, 4 and 5 of Perlman et al. (2002) that were obtained from the CDS. This is a service provided by NASA HEASARC .

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