- ID:
- ivo://CDS.VizieR/J/MNRAS/412/1853
- Title:
- Unidentified X-ray sources in XMM Slew Survey
- Short Name:
- J/MNRAS/412/1853
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep Swift follow-up observations of a sample of 94 unidentified X-ray sources from the XMM-Newton Slew Survey. The X-ray Telescope (XRT) on-board Swift detected 29 per cent of the sample sources; the flux limits for undetected sources suggest the bulk of the Slew Survey sources are drawn from one or more transient populations. We report revised X-ray positions for the XRT-detected sources, with typical uncertainties of 2.9 arcsec, reducing the number of catalogued optical matches to just a single source in most cases. We characterize the sources detected by Swift through their X-ray spectra and variability and via Ultraviolet-Optical Telescope photometry and using catalogued near-infrared, optical and radio observations of potential counterparts. Six sources can be associated with known objects and eight sources may be associated with unidentified ROSAT sources within the 3{sigma} error radii of our revised X-ray positions.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/129/927
- Title:
- Unresolved H{alpha} enhancements in WHAM survey
- Short Name:
- J/AJ/129/927
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified 85 regions of enhanced H{alpha} emission at |b|>10{deg} subtending approximately 1{deg} or less on the Wisconsin H{alpha} Mapper (WHAM) sky survey (Cat. II/249). These high-latitude "WHAM point sources" have H{alpha} fluxes of 10^-11^-10^-9^ergs/cm^2^/s, radial velocities within about 70km/s of the LSR, and line widths that range from less than 20 to about 80km/s (FWHM). Twenty-nine of these enhancements are not identified with either cataloged nebulae or hot stars and appear to have kinematic properties that differ from those observed for planetary nebulae. Another 14 enhancements are near hot evolved low-mass stars that had no previously reported detections of associated nebulosity. The remainder of the enhancements are cataloged planetary nebulae and small, high-latitude HII regions surrounding massive O and early B stars.
- ID:
- ivo://CDS.VizieR/J/AJ/160/279
- Title:
- Untangling the Galaxy. II. Structure within 3kpc
- Short Name:
- J/AJ/160/279
- Date:
- 09 Mar 2022 22:00:00
- Publisher:
- CDS
- Description:
- We present the results of the hierarchical clustering analysis of the Gaia DR2 data to search for clusters, comoving groups, and other stellar structures. The current paper builds on the sample from the previous work, extending it in distance from 1 to 3kpc and increasing the number of identified structures up to 8292. To aid in the analysis of the population properties, we developed a neural network called Auriga to robustly estimate the age, extinction, and distance of a stellar group based on the input photometry and parallaxes of the individual members. We apply Auriga to derive the properties of not only the structures found in this paper, but also previously identified open clusters. Through this work, we examine the temporal structure of the spiral arms. Specifically, we find that the Sagittarius Arm has moved by >500pc in the last 100Myr and the Perseus Arm has been experiencing a relative lull in star formation activity over the last 25Myr. We confirm the findings of the previous paper on the transient nature of the spiral arms, with the timescale of transition of a few 100Myr. Finally, we find a peculiar ~1Gyr old stream of stars that appears to be heliocentric. Its origin is unclear.
- ID:
- ivo://CDS.VizieR/J/ApJ/839/88
- Title:
- 14 unusual IR transients with Spitzer (SPRITEs)
- Short Name:
- J/ApJ/839/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an ongoing, five-year systematic search for extragalactic infrared transients, dubbed SPIRITS-SPitzer InfraRed Intensive Transients Survey. In the first year, using Spitzer/IRAC, we searched 190 nearby galaxies with cadence baselines of one month and six months. We discovered over 1958 variables and 43 transients. Here, we describe the survey design and highlight 14 unusual infrared transients with no optical counterparts to deep limits, which we refer to as SPRITEs (eSPecially Red Intermediate-luminosity Transient Events). SPRITEs are in the infrared luminosity gap between novae and supernovae, with [4.5] absolute magnitudes between -11 and -14 (Vega-mag) and [3.6]-[4.5] colors between 0.3mag and 1.6mag. The photometric evolution of SPRITEs is diverse, ranging from <0.1mag/yr to >7mag/yr. SPRITEs occur in star-forming galaxies. We present an in-depth study of one of them, SPIRITS 14ajc in Messier 83, which shows shock-excited molecular hydrogen emission. This shock may have been triggered by the dynamic decay of a non-hierarchical system of massive stars that led to either the formation of a binary or a protostellar merger.
- ID:
- ivo://CDS.VizieR/J/ApJ/869/56
- Title:
- Updated calibration of the CSP-I SNe Ia sample
- Short Name:
- J/ApJ/869/56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the final data release of the Carnegie Supernova Project I (CSP-I; Krisciunas+ 2017, J/AJ/154/211), focusing on the absolute calibration of the luminosity-decline rate relation for Type Ia supernovae (SNe Ia) using new intrinsic color relations with respect to the color-stretch parameter, s_BV_, enabling improved dust extinction corrections. We investigate to what degree the so-called fast-declining SNe Ia can be used to determine accurate extragalactic distances. We estimate the intrinsic scatter in the luminosity-decline rate relation and find it ranges from +/-0.13mag to +/-0.18mag with no obvious dependence on wavelength. Using the Cepheid variable star data from the SH0ES project (Riess+ 2016, J/ApJ/826/56), the SN Ia distance scale is calibrated and the Hubble constant is estimated using our optical and near-infrared sample, and these results are compared to those determined exclusively from a near-infrared subsample. The systematic effect of the supernova's host galaxy mass is investigated as a function of wavelength and is found to decrease toward redder wavelengths, suggesting this effect may be due to dust properties of the host. Using estimates of the dust extinction derived from optical and near-infrared wavelengths and applying these to the H band, we derive a Hubble constant H0=73.2+/-2.3km/s/Mpc, whereas using a simple B-V color correction applied to the B band yields H0=72.7+/-2.1km/s/Mpc. Photometry of two calibrating SNe Ia from the CSP-II sample, SN 2012ht and SN 2015F, is presented and used to improve the calibration of the SN Ia distance ladder.
- ID:
- ivo://CDS.VizieR/J/ApJS/220/6
- Title:
- Updated catalog of GALEX nearby galaxies
- Short Name:
- J/ApJS/220/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ultraviolet (UV) catalog of nearby galaxies compiled by Gil de Paz et al. (2007, J/ApJS/173/185) presents the integrated photometry and surface brightness profiles for 1034 nearby galaxies observed by GALEX. We provide an updated catalog of 4138 nearby galaxies based on the latest General Release (GR6/GR7) of GALEX. These galaxies are selected from HyperLeda with apparent diameters larger than 1'. From the surface brightness profiles accurately measured using the deep NUV and FUV images, we have calculated the asymptotic magnitudes, aperture (D25) magnitudes, colors, structural parameters (effective radii and concentration indices), luminosities, and effective surface brightness for these galaxies. Archival optical and infrared photometry from HyperLeda, 2MASS, and IRAS are also integrated into the catalog. Our parameter measurements and some analyses are consistent with those of Paz et al. The (FUV-K) color provides a good criterion to distinguish between early- and late-type galaxies, which can be improved further using the concentration indices. The IRX-{beta} relation is reformulated with our UV-selected nearby galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJS/238/4
- Title:
- Updated cat. of Algol-type binaries from CSSs
- Short Name:
- J/ApJS/238/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an updated catalog of 4680 northern eclipsing binaries (EBs) with Algol-type light-curve (LC) morphology (i.e., with well-defined beginnings and ends of primary and secondary eclipses), using data from the Catalina Sky Surveys. Our work includes revised period determinations, phenomenological parameters of the LCs, and system morphology classifications based on machine-learning techniques. While most of the new periods are in excellent agreement with those provided in the original Catalina catalogs, improved values are now available for ~10% of the stars. A total of 3456 EBs were classified as detached and 449 were classified as semi-detached, while 145 could not be classified unambiguously into either subtype. The majority of the SD systems seem to be comprised of short-period Algols. By applying color criteria, we searched for K- and M-type dwarfs in these data, and present a subsample of 609 EB candidates for further investigation. We report 119 EBs (2.5% of the total sample) that show maximum quadrature light variations over long timescales, with periods bracketing the range 4.5-18 years and a fractional luminosity variance range of 0.04-0.13. We discuss possible causes for this, making use of models of variable starspot activity in our interpretation of the results.
- ID:
- ivo://CDS.VizieR/J/AJ/159/82
- Title:
- Updated cat. of extended objects in Magellanic clouds
- Short Name:
- J/AJ/159/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of star clusters, associations, and related extended objects in the Small Magellanic Cloud (SMC) and the Magellanic Bridge with 2741 entries, a factor 2 more than a previous version from a decade ago. Literature data up until 2018 December are included. The identification of star clusters was carried out with digital atlases in various bands currently available in the Digitized Sky Survey (DSS) and the Machine Automatique a Mesurer pour l'Astronomie (MAMA) imaging surveys. In particular, we cross-identified recent cluster samples from the Visible and Infrared Survey Telescope for Astronomy (VISTA) near-infrared YJKs survey of the Magellanic System (VMC; Rubele+, 2015, J/MNRAS/449/639), Optical Gravitational Lensing Experiment IV (OGLE IV; Sitek+ 2017, J/AcA/67/363), and Survey of the MAgellanic Stellar History (SMASH; Piatti 2017ApJ...834L..14P) surveys, confirming new clusters and pointing out equivalencies. A major contribution of the present catalog consists of the accurate central positions for clusters and small associations, including a new sample of 45 clusters or candidates in the SMC and 19 in the Magellanic Bridge, as well as a compilation of the most reliable age and metallicity values from the literature. A general catalog must also deal with the recent discoveries of 27 faint and ultra-faint star clusters and galaxies projected on the far surroundings of the Clouds, most of them from the Dark Energy Survey. The information on these objects has been complemented with photometric, spectroscopic, and kinematical follow-up data from the literature. The underluminous galaxies around the Magellanic System, still very few as compared to the predictions from {Lambda} Cold Dark Matter simulations, can bring constraints to galaxy formation and hierarchical evolution. Furthermore, we provide diagnostics, when possible, of the nature of the ultra-faint clusters, searching for borders of the Magellanic System extensions into the Milky Way gravitational potential.
- ID:
- ivo://CDS.VizieR/J/ApJS/235/6
- Title:
- Updated Multiple Star Catalog (MSC): Sept 2021
- Short Name:
- J/ApJS/235/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog of hierarchical stellar systems with three or more components is an update of the original 1997 version (Tokovinin, 1997-1999, J/A+AS/124/75). For 2000 hierarchies, the new Multiple Star Catalog (MSC) provides distances, component masses and periods, and supplementary information (astrometry, photometry, identifiers, orbits, notes). The MSC content and format are explained, and its incompleteness and strong observational selection are stressed. Nevertheless, the MSC can be used for statistical studies and is a valuable source for planning observations of multiple stars. Rare classes of stellar hierarchies found in the MSC (with six or seven components, extremely eccentric orbits, planar and possibly resonant orbits, hosting planets) are briefly presented. High-order hierarchies have smaller velocity dispersion compared to triples and are often associated with moving groups. The paper concludes with an analysis of the ratio of periods and separations between inner and outer subsystems. In wide hierarchies, the ratio of semimajor axes, estimated statistically, is distributed between 3 and 300, with no evidence of dynamically unstable systems.
- ID:
- ivo://CDS.VizieR/J/AJ/145/101
- Title:
- Updated nearby galaxy catalog
- Short Name:
- J/AJ/145/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an all-sky catalog of 869 nearby galaxies having individual distance estimates within 11Mpc or corrected radial velocities V_LG_<600km/s. The catalog is a renewed and expanded version of the Catalog of Neighboring Galaxies by Karachentsev et al (2004, cat. J/AJ/127/2031). It collects data on the following galaxy observables: angular diameters, apparent magnitudes in far-UV, B, and K_s_bands, H{alpha} and HI fluxes, morphological types, HI-line widths, radial velocities, and distance estimates. In this Local Volume (LV) sample, 108 dwarf galaxies still remain without measured radial velocities. The catalog yields also calculated global galaxy parameters: linear Holmberg diameter, absolute B magnitude, surface brightness, HI mass, stellar mass estimated via K-band luminosity, HI rotational velocity corrected for galaxy inclination, indicative mass within the Holmberg radius, and three kinds of "tidal index," which quantify the local density environment. The catalog is supplemented with data based on the local galaxies, which presents their optical and available H{alpha} images, as well as other services. We briefly discuss the Hubble flow within the LV and different scaling relations that characterize galaxy structure and global star formation in them. We also trace the behavior of the mean stellar mass density, HI-mass density, and star formation rate density within the volume considered.
