- ID:
- ivo://CDS.VizieR/J/ApJS/96/605
- Title:
- Far UV Stellar Photometry
- Short Name:
- J/ApJS/96/605
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Far-ultraviolet photometry for 741 objects in a field in Sagittarius centered near M8 and 541 objects in a field centered near zeta Scorpii is presented. These data were extracted from electrographic images obtained with two cameras during a shuttle flight in 1991 April/May. The cameras provided band passes with lambda_eff = 1375 A and lambda_eff = 1781 A. Synthetic colors show that these bands are sensitive to effective temperature for hot stars. Our measurements were placed on a quantitative far-ultraviolet magnitude scale by convolving the spectra of stars observed by IUE with our cameras' spectral response functions. Fifty-eight percent of the ultraviolet objects were identified with visible stars using the SIMBAD database while another 40% of the objects are blends of early type stars too close together to separate with our resolution. Our photometry is compared with that from the TD-1, OAO 2, and ANS satellites and the S201 (Apollo 16) far-ultraviolet camera and found to agree at the level of a few tenths of a magnitude. Unlike previous studies, almost half of the identified visual counterparts to the ultraviolet objects are early B stars. A plot of distance modulus against ultraviolet color excess reveals a significant population of stars with strong ultraviolet excesses.
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- ID:
- ivo://CDS.VizieR/J/ApJS/104/101
- Title:
- Far-UV stellar photometry
- Short Name:
- J/ApJS/104/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Far-ultraviolet photometry is presented for 121 objects in a 20deg diameter field centered on Rho Oph and for 649 objects in a field covering the Galactic center. Broadband magnitudes with effective wavelengths of 1375A and 1781A are given. The Galactic center field overlaps two fields which were discussed in an earlier paper. Eighty- eight percent of the ultraviolet objects in the Rho Oph field were identified with visible stars using the SIMBAD database, while only 9% of the objects are blends of early-type stars too close together to separate with our resolution. The photometric calibration was studied in detail, and corrections for nonlinearity were derived for the fields analyzed earlier as well as those discussed here. For stars in common between the Galactic center field and the previous fields, a comparison of the magnitudes yielded estimates of the internal errors of the magnitudes of sigma_1375=0.13mag and sigma_1781=0.21mag. A collated list of stars in the fields covering the Galactic center and incorporating the revised calibration is presented and compared with the S201 data of the same region. The properties of the sample of ultraviolet objects in the Rho Oph field are briefly commented upon.
- ID:
- ivo://xaovo/fast_pul/q/q
- Title:
- FAST Pulsar Data Query Test
- Short Name:
- Pulsar_web
- Date:
- 25 Jun 2024 10:32:03
- Publisher:
- Xinjiang Astronomical Observatory,CAS
- Description:
- The data could only be used with the permission of Dr. Na Wang (na.wang@xao.ac.cn), please send her an email for your request.
- ID:
- ivo://CDS.VizieR/J/ApJ/888/40
- Title:
- Fast radio bursts with AstroSat/CZTI
- Short Name:
- J/ApJ/888/40
- Date:
- 07 Dec 2021
- Publisher:
- CDS
- Description:
- Fast radio bursts (FRBs) are short-lived (~ms), energetic transients (having a peak flux density of ~Jy) with no known prompt emission in other energy bands. We present results of a search for prompt X-ray emissions from 41 FRBs using the Cadmium Zinc Telluride Imager (CZTI) on AstroSat, which continuously monitors ~70% of the sky. Our searches on various timescales in the 20-200keV range, did not yield any counterparts in this hard X-ray band. We calculate upper limits on hard X-ray flux, in the same energy range and convert them to upper bounds for {eta}: the ratio of X-ray to radio fluence of FRBs. We find {eta}<=10^8-10^ for hard X-ray emission. Our results will help constrain the theoretical models of FRBs as the models become more quantitative and nearer, brighter FRBs are discovered.
- ID:
- ivo://CDS.VizieR/J/MNRAS/407/465
- Title:
- Fast-rotating M dwarfs in NGC2516
- Short Name:
- J/MNRAS/407/465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report radial velocities (RVs), projected equatorial velocities (vsini) and CaII triplet (CaT) chromospheric activity indices for 237 late-K to mid-M candidate members of the young open cluster NGC 2516. These stars have published rotation periods between 0.1 and 15d. Intermediate-resolution spectra were obtained using the Giraffe spectrograph at the Very Large Telescope. Membership was confirmed on the basis of their RVs for 210 targets.
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/2099
- Title:
- Fast-rotating M-dwarf stars in NGC 2547
- Short Name:
- J/MNRAS/411/2099
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- At fast rotation rates, the coronal activity of G- and K-type stars has been observed to "saturate" and then decline again at even faster rotation rates - a phenomenon dubbed "supersaturation". In this paper, we investigate coronal activity in fast-rotating M-dwarfs using deep XMM-Newton observations of 97 low-mass stars of known rotation period in the young open cluster NGC 2547 and combine these with published X-ray surveys of low-mass field and cluster stars of known rotation period.
- ID:
- ivo://CDS.VizieR/J/A+A/384/491
- Title:
- Fast-rotating nearby solar-type stars. I.
- Short Name:
- J/A+A/384/491
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of high-resolution spectroscopic and high-precision photometric observations on a sample of 129 late-F and G-type nearby stars selected on the basis of their large rotational velocity. Using also data from the Hipparcos satellite, CORAVEL and from the ROSAT satellite database, we infer spectral types, compute radial velocities, vsini, Li abundances and X-ray luminosities and investigate the single or binary nature of the sample stars. Such a careful analysis of our sample shows a large fraction of binaries (~62%) and of young single disk stars. In particular, at least 9 stars can be considered bona-fide PMS or ZAMS objects, and 30 stars are identified as SBs for the first time. Information on the presence of Ca II K emission and on optical variability is given for some of the stars of the sample. The photometry has been obtained at the European Southern Observatory (ESO-La silla, Chile) during several observing runs (19/11-03/12 1993, 24/11-04/12 1994, 15-28/01/1995 and 1-12/10/1995), by using the 50cm ESO telescope. The figures were published in paper II.
- ID:
- ivo://CDS.VizieR/J/ApJ/682/1205
- Title:
- Fast transients in the Fornax cluster
- Short Name:
- J/ApJ/682/1205
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The luminosity gap between novae (M_R_<=-10) and supernovae (M_R_>=-14) has been well known since the pioneering research of Zwicky and Hubble. Nearby galaxy clusters and concentrations offer an excellent opportunity to search for explosions brighter than classical novae and fainter than supernovae. Here we present the results of a B-band survey of 23 member galaxies of the Fornax Cluster, performed at the Las Campanas 2.5m Irenee du Pont telescope. Observations with a cadence of 32 minutes discovered no genuine fast transient to a limiting absolute magnitude of M_B_=-9.3mag. We provide a detailed assessment of the transient detection efficiency and the resulting upper limits on the event rate as function of peak magnitude. Further, we discuss the discoveries of five previously unknown foreground variables which we identified as two flare stars, two W UMa-type eclipsing binaries and a candidate {delta} Scuti/SX Phe star.
- ID:
- ivo://nasa.heasarc/faust
- Title:
- Faust Far-UV Point Source Catalog
- Short Name:
- FAUST
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog contains a list of the photometric measurements of point sources made by the Far Ultraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 space shuttle mission. The list contains 4660 galactic and extragalactic objects detected in 22 wide-field images of the sky (note that the abstract of the published catalog states that it contains 4698 sources: the reason for this discrepancy is not known to the HEASARC). At the locations surveyed, this catalog reaches a limiting magnitude that is approximately a factor of 10 fainter than the previous UV all-sky survey, TD1. The catalog limit is approximately 1x10<sup>-14</sup> ergs/s/cm<sup>2</sup>/Angstrom, although it is not complete to this level. Listed for each object is the position, Far-UV (FUV) flux, the error in this flux, and, where possible, an identification from catalogs of nearby stars and galaxies. These catalogs include the Michigan HD (MHD) and HD Catalogs, the SAO Catalog, the HIPPARCOS Input Catalog (HIC), the Position and Proper Motion (PPM) Catalog, the TD1 Catalog, the McCook and Sion Catalog of white dwarf stars, and the RC3 Catalog of Galaxies. 2239 FAUST sources are identified with objects in the stellar catalogs and 172 with galaxies in the RC3 catalog. The number of sources with incorrect identifications is estimated to be less than 2%. Of the 4660 FUV sources in this catalog, 161 have multiple stellar and/or galaxy counterparts (155 sources have 2 possible counterparts, 4 sources have 3 possible counterparts, 1 source has 4 possible counterparts, and 1 source has 6 possible counterparts), with the 4499 remaining FUV sources having 0 or 1 stellar and/or galaxy counterparts. Hence, there are a grand total of 4831 = (4499 + 155x2 + 4x3 + 1x4 + 1x6) entries in this database, since each entry corresponds to a source/counterpart combination. The HEASARC added a parameter 'multiple_ID' to allow the user to identify sources with multiple possible counterparts. FAUST Sources with multiple counterparts thus have multiple entries in this database, and can be recognized by having multiple_id values greater than 1 (and differing information in the parameter fields that contain the properties of the stellar and/or galaxy counterparts). This catalog was created at the HEASARC in September 1998 based on CDS/ADC Catalog J/ApJS/96/461. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/MNRAS/313/641
- Title:
- FAUST observations in 4th Galactic Quadrant
- Short Name:
- J/MNRAS/313/641
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The UV observations of FAUST are analysed in four sky fields (Dor, Cen, M81 and Tel), located in the general direction of the Fourth Galactic Quadrant, where 777 UV sources are detected, about 50% more than detected originally by Bowyer et al. (1993ApJ...415..875B). Ground-based objective-prism information for two of the fields were used to select the best-matching optical objects with which to identify the UV sources. Using this, and correlations with existing catalogues, reliable identifications are presented for about 75% of the sources. Most of the remaining sources have assigned optical counterparts but, lacking additional information, we offer only plausible identifications. FAUST is a wide-field telescope (7.6{deg} diameter) designed to image diffuse and point sources in the wavelength range 140-180nm. The experiment, the mission and the data are described in a previous paper by Bowyer et al., 1993ApJ...415..875B .