- ID:
- ivo://CDS.VizieR/J/A+A/418/927
- Title:
- RXTE All-Sky Slew Survey catalog, |b|>10{deg}
- Short Name:
- J/A+A/418/927
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results of a serendipitous hard X-ray (3-20keV), nearly all-sky (|b|>10{deg}) survey based on RXTE/PCA observations performed during satellite reorientations in 1996-2002. The survey is 80% (90%) complete to a 4{sigma} limiting flux of ~1.8 (2.5)x10^-11^erg/s/cm^2^ in the 3-20keV band. The achieved sensitivity in the 3-8keV and 8-20keV subbands is similar to and an order of magnitude higher than that of the previously record HEAO-1 A1 and HEAO-1 A4 all-sky surveys, respectively. A combined 7x10^3^~sq.deg area of the sky is sampled to flux levels below 10^-11^erg/s/cm^2^ (3-20keV). In total 294 sources are detected and localized to better than ~1{deg}. 236 (80%) of these can be confidently associated with a known astrophysical object; another 22 likely result from the superposition of 2 or 3 closely located known sources. 35 detected sources remain unidentified, although for 12 of these we report a likely soft X-ray counterpart from the ROSAT all-sky survey bright source catalog. Of the reliably identified sources, 63 have local origin (Milky Way, LMC or SMC), 64 are clusters of galaxies and 100 are active galactic nuclei (AGN). The fact that the unidentified X-ray sources have hard spectra suggests that the majority of them are AGN, including highly obscured ones (N_H_>10^23^cm^-2^). For the first time we present a logN-logS diagram for extragalactic sources above 4x10^-12^erg/s/cm^2^ at 8-20keV.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/217/17
- Title:
- SAFIRES: Spitzer Archival FIR Extragalactic Survey
- Short Name:
- J/ApJS/217/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Spitzer Archival Far-InfraRed Extragalactic Survey (SAFIRES). This program produces refined mosaics and source lists for all far-infrared (FIR) extragalactic data taken during the more than six years of the cryogenic operation of the Spitzer Space Telescope. The SAFIRES products consist of FIR data in two wavelength bands (70 and 160{mu}m) across approximately 180 square degrees of sky, with source lists containing far-infrared fluxes for almost 40000 extragalactic point sources. Thus, SAFIRES provides a large, robust archival far-infrared data set suitable for many scientific goals.
- ID:
- ivo://CDS.VizieR/J/ApJ/787/110
- Title:
- SAGA: Stromgren survey of seismic KIC stars
- Short Name:
- J/ApJ/787/110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Asteroseismology has the capability of precisely determining stellar properties that would otherwise be inaccessible, such as radii, masses, and thus ages of stars. When coupling this information with classical determinations of stellar parameters, such as metallicities, effective temperatures, and angular diameters, powerful new diagnostics for Galactic studies can be obtained. The ongoing Stromgren survey for Asteroseismology and Galactic Archaeology (SAGA) has the goal of transforming the Kepler field into a new benchmark for Galactic studies, similar to the solar neighborhood. Here we present the first results from a stripe centered at a Galactic longitude of 74{deg} and covering latitude from about 8{deg} to 20{deg}, which includes almost 1000 K giants with seismic information and the benchmark open cluster NGC 6819. We describe the coupling of classical and seismic parameters, the accuracy as well as the caveats of the derived effective temperatures, metallicities, distances, surface gravities, masses, and radii. Confidence in the achieved precision is corroborated by the detection of the first and secondary clumps in a population of field stars with a ratio of 2 to 1 and by the negligible scatter in the seismic distances among NGC 6819 member stars. An assessment of the reliability of stellar parameters in the Kepler Input Catalog is also performed, and the impact of our results for population studies in the Milky Way is discussed, along with the importance of an all-sky Stromgren survey.
1494. SAGE calibration stars
- ID:
- ivo://CDS.VizieR/J/AJ/132/2268
- Title:
- SAGE calibration stars
- Short Name:
- J/AJ/132/2268
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We are performing a uniform and unbiased imaging survey of the Large Magellanic Cloud (LMC; ~7{deg}x7{deg}) using the IRAC (3.6, 4.5, 5.8, and 8um) and MIPS (24, 70, and 160um) instruments on board the Spitzer Space Telescope in the Surveying the Agents of a Galaxy's Evolution (SAGE) survey, these agents being the interstellar medium (ISM) and stars in the LMC. This paper provides an overview of the SAGE Legacy project, including observing strategy, data processing, and initial results. The observing strategy includes two epochs in 2005, separated by 3 months, that both mitigate instrumental artifacts and constrain source variability. The SAGE data are nonproprietary. The data processing includes IRAC and MIPS pipelines and a database for mining the point-source catalogs, which will be released to the community in support of Spitzer proposal cycles 4 and 5. We present initial results on the epoch 1 data for a region near N79 and N83. The MIPS 70 and 160um images of the diffuse dust emission of the N79/N83 region reveal a similar distribution to the gas emissions, especially the HI 21cm emission.
- ID:
- ivo://CDS.VizieR/J/ApJ/778/15
- Title:
- SAGE-SMC III. Young stellar objects
- Short Name:
- J/ApJ/778/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Space Telescope Legacy Program SAGE-SMC allows global studies of resolved stellar populations in the SMC in a different environment than our Galaxy. Using the SAGE-SMC IRAC (3.6-8.0{mu}m) and MIPS (24 and 70{mu}m) catalogs and images combined with near-infrared (JHK_s_) and optical (UBVI) data, we identified a population of ~1000 intermediate - to high-mass young stellar objects (YSOs) in the SMC (three times more than previously known). Our method of identifying YSO candidates builds on the method developed for the Large Magellanic Cloud by Whitney et al. (2008, J/AJ/136/18) with improvements based on what we learned from our subsequent studies and techniques described in the literature. We perform (1) color-magnitude cuts based on five color-magnitude diagrams (CMDs), (2) visual inspection of multi-wavelength images, and (3) spectral energy distribution (SED) fitting with YSO models. For each YSO candidate, we use its photometry to calculate a measure of our confidence that the source is not a non-YSO contaminant, but rather a true YSO, based on the source's location in the color-magnitude space with respect to non-YSOs. We use this CMD score and the SED fitting results to define two classes of sources: high-reliability YSO candidates and possible YSO candidates. We found that, due to polycyclic aromatic hydrocarbon emission, about half of our sources have [3.6]-[4.5] and [4.5]-[5.8] colors not predicted by previous YSO models. The YSO candidates are spatially correlated with gas tracers.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/123
- Title:
- SAMI Galaxy Survey asymmetries
- Short Name:
- J/MNRAS/465/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the properties of kinematically disturbed galaxies in the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey using a quantitative criterion, based on kinemetry (Krajnovic et al., 2011MNRAS.414.2923K). The approach, similar to the application of kinemetry by Shapiro et al., uses ionized gas kinematics, probed by H{alpha} emission. By this method, 23+/-7 per cent of our 360-galaxy sub-sample of the SAMI Galaxy Survey are kinematically asymmetric. Visual classifications agree with our kinemetric results for 90 per cent of asymmetric and 95 per cent of normal galaxies. We find that stellar mass and kinematic asymmetry are inversely correlated and that kinematic asymmetry is both more frequent and stronger in low-mass galaxies. This builds on previous studies that found high fractions of kinematic asymmetry in low-mass galaxies using a variety of different methods. Concentration of star formation and kinematic disturbance are found to be correlated, confirming results found in previous work. This effect is stronger for high-mass galaxies (log(M*)>10) and indicates that kinematic disturbance is linked to centrally concentrated star formation. Comparison of the inner (within 0.5Re) and outer H{alpha} equivalent widths of asymmetric and normal galaxies shows a small but significant increase in inner equivalent width for asymmetric galaxies.
1497. SAMI Galaxy Survey: EDR
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/1567
- Title:
- SAMI Galaxy Survey: EDR
- Short Name:
- J/MNRAS/446/1567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Early Data Release of the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey. The SAMI Galaxy Survey is an ongoing integral field spectroscopic survey of ~3400 low-redshift (z<0.12) galaxies, covering galaxies in the field and in groups within the Galaxy And Mass Assembly (GAMA) survey regions, and a sample of galaxies in clusters. In the Early Data Release, we publicly release the fully calibrated data cubes for a representative selection of 107 galaxies drawn from the GAMA regions, along with information about these galaxies from the GAMA catalogues. All data cubes for the Early Data Release galaxies can be downloaded individually or as a set from the SAMI Galaxy Survey website. In this paper we also assess the quality of the pipeline used to reduce the SAMI data, giving metrics that quantify its performance at all stages in processing the raw data into calibrated data cubes. The pipeline gives excellent results throughout, with typical sky subtraction residuals in the continuum of 0.9-1.2 per cent, a relative flux calibration uncertainty of 4.1 per cent (systematic) plus 4.3 per cent (statistical), and atmospheric dispersion removed with an accuracy of 0.09-arcsec, less than a fifth of a spaxel.
- ID:
- ivo://CDS.VizieR/J/ApJ/835/104
- Title:
- SAMI Galaxy Survey: rotators classification
- Short Name:
- J/ApJ/835/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h_3_ (~skewness) and h_4_ (~kurtosis) in galaxies to their cosmological assembly history. Here, we assess these results by measuring the stellar kinematics on a sample of 315 galaxies, without a morphological selection, using two-dimensional integral field data from the SAMI Galaxy Survey. Proxies for the spin parameter ({lambda}R_e_) and ellipticity ({epsilon}_e_) are used to separate fast and slow rotators; there exists a good correspondence to regular and non-regular rotators, respectively, as also seen in earlier studies. We confirm that regular rotators show a strong h_3_ versus V/{sigma} anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h_3_ and V/{sigma}. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h_3_ versus V/{sigma} signatures. Within the SAMI Galaxy Survey, we identify five classes of high-order stellar kinematic signatures using Gaussian mixture models. Class 1 corresponds to slow rotators, whereas Classes 2-5 correspond to fast rotators. We find that galaxies with similar {lambda}R_e_-{epsilon}_e_ values can show distinctly different h_3_-V/{sigma} signatures. Class 5 objects are previously unidentified fast rotators that show a weak h_3_ versus V/{sigma} anti-correlation. From simulations, these objects are predicted to be disk-less galaxies formed by gas-poor mergers. From morphological examination, however, there is evidence for large stellar disks. Instead, Class 5 objects are more likely disturbed galaxies, have counter-rotating bulges, or bars in edge-on galaxies. Finally, we interpret the strong anti-correlation in h_3_ versus V/{sigma} as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators.
- ID:
- ivo://CDS.VizieR/J/MNRAS/423/2690
- Title:
- Sample of Compact Group (CG) galaxies
- Short Name:
- J/MNRAS/423/2690
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct a sample of 75863 star-forming galaxies with robust metallicity and star formation rate (SFR) measurements from the Sloan Digital Sky Survey Data Release 7, from which we select a clean sample of compact group (CG) galaxies. The CGs are defined to be close configurations of at least four galaxies that are otherwise apparently isolated. Our selection results in a sample of 112 spectroscopically identified CG galaxies, which can be further divided into groups that are either embedded within a larger structure, such as a cluster or large group, or truly isolated systems. The CGs then serve as a probe into the influence of large-scale environment on a galaxy's evolution, while keeping the local density fixed at high values. W
- ID:
- ivo://CDS.VizieR/J/MNRAS/468/77
- Title:
- Sample of confirmed quasar pairs
- Short Name:
- J/MNRAS/468/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the most precise estimate to date of the clustering of quasars on very small scales, based on a sample of 47 binary quasars with magnitudes of g < 20.85 and proper transverse separations of ~25h^-1^kpc. Our sample of binary quasars, which is about six times larger than any previous spectroscopically confirmed sample on these scales, is targeted using a kernel density estimation (KDE) technique applied to Sloan Digital Sky Survey (SDSS) imaging over most of the SDSS area. Our sample is 'complete' in that all of the KDE target pairs with 17.0<=R<=36.2h^-1^kpc in our area of interest have been spectroscopically confirmed from a combination of previous surveys and our own long-slit observational campaign. We catalogue 230 candidate quasar pairs with angular separations of <8 arcsec, from which our binary quasars were identified. We determine the projected correlation function of quasars (<W>_ p_) in four bins of proper transverse scale over the range 17.0<=R<=36.2h^-1^kpc. The implied small-scale quasar clustering amplitude from the projected correlation function, integrated across our entire redshift range, is A=24.1+/-3.6 at ~26.6h^-1^kpc. Our sample is the first spectroscopically confirmed sample of quasar pairs that is sufficiently large to study how quasar clustering evolves with redshift at ~25h^-1^kpc. We find that empirical descriptions of how quasar clustering evolves with redshift at ~25h^-1^Mpc also adequately describe the evolution of quasar clustering at ~25h^-1^kpc.
