- ID:
- ivo://CDS.VizieR/J/ApJ/703/30
- Title:
- NIR counterparts to Chandra X-ray sources. I.
- Short Name:
- J/ApJ/703/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 5184 candidate infrared counterparts to X-ray sources detected toward the Galactic center. The X-ray sample contains 9017 point sources detected in this region by the Chandra X-ray Observatory during the past decade, including data from a recent deep survey of the central 2{deg}x0.8{deg} of the Galactic plane. A total of 6760 of these sources have hard X-ray colors, and the majority of them lie near the Galactic center, while most of the remaining 2257 soft X-ray sources lie in the foreground. We cross-correlated the X-ray source positions with the 2MASS and SIRIUS near-infrared catalogs, which collectively contain stars with a 10{sigma} limiting flux of Ks<=15.6mag. For each of the infrared matches to X-ray sources in our catalog we derived the probability that the association is real, based on the source properties and the results of the cross-correlation analysis.
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Search Results
- ID:
- ivo://CDS.VizieR/J/PASP/120/1183
- Title:
- NIR fluxes of 14 cool variable stars
- Short Name:
- J/PASP/120/1183
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New flux data are presented for nine non-variable stars and 14 evolved variable stars with spectral types M and C. The data are from measurements of 21 passbands in the wavelength range from 7440{AA} to 10834{AA}, and they are comparable to measurements made by Wing some 40 years ago. Because the extinction algorithm applied to the new data is based partly on up-to-date calculations of telluric water-vapor effects, those calculations are tested for accuracy. In addition, methods used to calibrate standard stars both outside and inside the Paschen confluence are explained. After reddening corrections are applied to the flux data for the variable stars, those data are used to calculate color temperatures. In turn, those temperatures are used to derive blanketing corrections to color temperatures measured in the Wing filter system. Indices of absorption strength are calculated by comparing the flux data to blackbody colors derived from the color temperatures. It is found that the standard errors of those temperatures range from 3% to less than 1%. For the variable stars, the standard errors for the flux data range from 6.8mmag to 11.6mmag. For the non-variable stars, the corresponding standard error is about 6.0mmag.
- ID:
- ivo://CDS.VizieR/J/ApJ/466/254
- Title:
- NIR Imaging of R136 in 30 Dor
- Short Name:
- J/ApJ/466/254
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 0.15" resolution near-infrared (NIR) imaging of R136, the central region of 30 Doradus in the Large Magellanic Cloud. Our 12.8"x12.8" images were recorded with the MPE camera SHARP II at the 3.6m ESO telescope, using the adaptive optics system COME ON+. The high spatial resolution and sensitivity (20th magnitude in K) of our observations allow our H- and K-band images to be compared and combined with recent Hubble Space Telescope (HST) WFPC2 data of R136. We fit theoretical models with variable foreground extinction to the observed magnitudes of ~1000 stars (roughly half of which were detected in HST and NIR bands) and derive the stellar population in this starburst region. We find no red giants or supergiants; however, we detect ~110 extremely red sources which are probably young, pre-main-sequence low- or intermediate-mass stars. We obtained narrow-band images to identify known and new Wolf-Rayet stars by their He II (2.189um) and BrGamma (2.166um) emission lines. The presence of W-R stars and absence of red supergiants narrow the cluster age to 3-5Myr, while the derived ratio of W-R to O stars of 0.05 in the central region favors an age of ~3.5Myr, with a relatively short starburst duration. For the O stars, the core radius is found to be 0.1pc and appears to decrease with increasing stellar mass. The slope of the mass function is Gamma=-1.6 on average, but it steepens with increasing distance from the cluster center from Gamma=-1.3 in the inner 0.4pc to Gamma=-2.2 outside 0.8pc for stars more massive than 12 Msun. The radial variation of the mass function reveals strong mass segregation that is probably due to the cluster's dynamical evolution.
- ID:
- ivo://CDS.VizieR/J/ApJ/777/160
- Title:
- NIR imaging survey for planets around MG stars
- Short Name:
- J/ApJ/777/160
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results of a direct imaging survey for giant planets around 80 members of the {beta} Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra moving groups, observed as part of the Gemini/NICI Planet-Finding Campaign. For this sample, we obtained median contrasts of {Delta}H=13.9mag at 1" in combined CH_4_ narrowband ADI+SDI mode and median contrasts of {Delta}H=15.1mag at 2" in H-band ADI mode. We found numerous (>70) candidate companions in our survey images. Some of these candidates were rejected as common-proper motion companions using archival data; we reobserved with Near-Infrared Coronagraphic Imager (NICI) all other candidates that lay within 400AU of the star and were not in dense stellar fields. The vast majority of candidate companions were confirmed as background objects from archival observations and/or dedicated NICI Campaign followup. Four co-moving companions of brown dwarf or stellar mass were discovered in this moving group sample: PZ Tel B (36+/-6M_Jup_, 16.4+/-1.0AU), CD-35 2722B (31+/-8M_Jup_, 67+/-4AU), HD 12894B (0.46+/-0.08M_{sun}_, 15.7+/-1.0AU), and BD+07 1919C (0.20+/-0.03M_{sun}_, 12.5+/-1.4AU). From a Bayesian analysis of the achieved H band ADI and ASDI contrasts, using power-law models of planet distributions and hot-start evolutionary models, we restrict the frequency of 1-20M_Jup_ companions at semi-major axes from 10-150AU to <18% at a 95.4% confidence level using DUSTY models and to <6% at a 95.4% using COND models. Our results strongly constrain the frequency of planets within semi-major axes of 50 AU as well. We restrict the frequency of 1-20M_Jup_ companions at semi-major axes from 10-50AU to <21% at a 95.4% confidence level using DUSTY models and to <7% at a 95.4% using COND models. This survey is the deepest search to date for giant planets around young moving group stars.
2045. NIR K-corrections
- ID:
- ivo://CDS.VizieR/J/A+A/615/A45
- Title:
- NIR K-corrections
- Short Name:
- J/A+A/615/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Type Ia Supernovae (SNe Ia) have been used as standardizable candles in the optical wavelengths to measure distances with an accuracy of ~7% out to redshift z~1.5. There is evidence that in the near-infrared (NIR) wavelengths SNe Ia are even better standard candles, however, NIR observations are much more time-consuming. We aim to test whether the NIR peak magnitudes could be accurately estimated with only a single observation obtained close to maximum light, provided that the time of B band maximum, the B-V color at maximum and the optical stretch parameter are known. We present multi-epoch UBVRI and single-epoch J and H photometric observations of 16 SNe Ia in the redshift range z=0.037-0.183, doubling the leverage of the current SN Ia NIR Hubble diagram and the number of SNe beyond redshift 0.04. This sample was analyzed together with 102 NIR and 458 optical light curves (LCs) of normal SNe Ia from the literature. Results. The analysis of 45 NIR LCs with well-sampled first maximum shows that a single template accurately describes the LCs if its time axis is stretched with the optical stretch parameter. This allows us to estimate the peak NIR magnitudes of SNe with only few observations obtained within ten days from B-band maximum. The NIR Hubble residuals show weak correlation with {Delta}M_15_ and the color excess E(B-V), and for the first time we report a potential dependence on the Jmax-Hmax color. With these corrections, the intrinsic NIR luminosity scatter of SNe Ia is estimated to be ~0.10mag, which is smaller than what can be derived for a similarly heterogeneous sample at optical wavelengths. Analysis of both NIR and optical data shows that the dust extinction in the host galaxies corresponds to a low RV~=1.8-1.9. We conclude that SNe Ia are at least as good standard candles in the NIR as in the optical and are potentially less affected by systematic uncertainties. We extended the NIR SN Ia Hubble diagram to its nonlinear part at z~0.2 and confirmed that it is feasible to accomplish this result with very modest sampling of the NIR LCs, if complemented by well-sampled optical LCs. With future facilities it will be possible to extend the NIR Hubble diagram beyond redshift z~=1, and our results suggest that the most efficient way to achieve this would be to obtain a single observation close to the NIR maximum.
- ID:
- ivo://CDS.VizieR/J/MNRAS/396/2367
- Title:
- NIR Ks photometry of Norma cluster (A3627)
- Short Name:
- J/MNRAS/396/2367
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A deep Ks-band photometric catalogue of galaxies at the core of the rich, nearby Norma cluster (ACO3627) is presented. The survey covers about 45x45arcmin^2^ (slightly less than 1/3 Abell radius), which corresponds to ~0.8h_70_^-2^Mpc^2^ at the adopted distance (v_CMB_/H_0_) of 70h_70_^-1^Mpc of this cluster. The survey is estimated to be complete to a magnitude of M_Ks_<~-19.5mag. This extends into the dwarf regime, 6mag below M*_Ks_. The catalogue contains 390 objects, 235 of which are classified as likely or definite galaxies and 155 as candidate galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/46
- Title:
- NIR LCs of RRab stars from the VVV survey
- Short Name:
- J/ApJ/898/46
- Date:
- 21 Mar 2022 07:11:54
- Publisher:
- CDS
- Description:
- Aiming to extend the census of RR Lyrae stars to highly reddened low-latitude regions of the central Milky Way, we performed a deep near-IR variability search using data from the VISTA Variables in the Via Lactea (VVV) survey of the bulge, analyzing the photometric time series of over a hundred million point sources. In order to separate fundamental-mode RR Lyrae (RRab) stars from other periodically variable sources, we trained a deep bidirectional long short-term memory recurrent neural network (RNN) classifier using VVV survey data and catalogs of RRab stars discovered and classified by optical surveys. Our classifier attained a ~99% precision and recall for light curves with signal-to-noise ratio above 60, and is comparable to the best-performing classifiers trained on accurate optical data. Using our RNN classifier, we identified over 4300 hitherto unknown bona fide RRab stars toward the inner bulge. We provide their photometric catalog and VVV J,H,Ks photometric time series.
- ID:
- ivo://CDS.VizieR/J/AJ/160/220
- Title:
- NIR light curve of 234 RR Lyrae in Messier 3
- Short Name:
- J/AJ/160/220
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new near-infrared (NIR), JHKs, time-series observations of RR-Lyrae variables in the Messier-3 (NGC5272) globular cluster using the WIRCam instrument at the 3.6m Canada-France-Hawaii Telescope. Our observations cover a sky area of ~21'x21' around the cluster center and provide an average of 20 epochs of homogeneous JHKs-band photometry. New homogeneous photometry is used to estimate robust mean magnitudes for 175 fundamental-mode (RRab), 47 overtone-mode (RRc), and 11 mixed-mode (RRd) variables. Our sample of 233 RR-Lyrae variables is the largest thus far obtained in a single cluster with time-resolved, multiband NIR photometry. NIR-to-optical amplitude ratios for RR-Lyrae in Messier-3 exhibit a systematic increase moving from RRc to short-period (P<0.6day) and long-period (P>~0.6day) RRab variables. We derive JHKs-band period-luminosity relations for RRab, RRc, and the combined sample of variables. Absolute calibrations based on the theoretically predicted period-luminosity-metallicity relations for RR Lyrae stars yield a distance modulus, {mu}=15.041{+/-}0.017(statistical){+/-}0.036(systematic)mag, to Messier-3. When anchored to trigonometric parallaxes for nearby RR-Lyrae stars from the Hubble Space Telescope and the Gaia mission, our distance estimates are consistent with those resulting from the theoretical calibrations, albeit with relatively larger systematic uncertainties.
- ID:
- ivo://CDS.VizieR/J/A+A/576/A30
- Title:
- NIR light-curve templates for classical Cepheids
- Short Name:
- J/A+A/576/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new near-infrared (NIR) light-curve templates for fundamental (FU, J, H, Ks) and first overtone (FO, J) classical Cepheids. The new templates together with period-luminosity and period-Wesenheit (PW) relations provide Cepheid distances from single-epoch observations with a precision only limited by the intrinsic accuracy of the method adopted. The templates rely on a very large set of Galactic and Magellanic Cloud Cepheids (FU, ~600; FO, ~200) with well-sampled NIR (IRSF data set) and optical (V, I; OGLE data set) light-curves. To properly trace the change in the shape of the light-curve as a function of pulsation period, we split the sample of calibrating Cepheids into ten different period bins. The templates for the first time cover FO Cepheids and the short-period range of FU Cepheids (P<=5-days). Moreover, the phase zero-point is anchored to the phase of the mean magnitude along the rising branch. The new approach has several advantages in sampling the light-curve of bump Cepheids when compared with the canonical phase of maximum light. We also provide new empirical estimates of the NIR-to-optical amplitude ratios for FU and FO Cepheids. We perform detailed analytical fits using seventh-order Fourier series and multi-Gaussian periodic functions. The latter are characterized by fewer free parameters (nine vs. fifteen). The mean NIR magnitudes based on the new templates are up to 80% more accurate than single-epoch NIR measurements and up to 50% more accurate than the mean magnitudes based on previous NIR templates, with typical associated uncertainties ranging from 0.015mag (J band) to 0.019mag (K_S_ band). Moreover, we find that errors on individual distance estimates for Small Magellanic Cloud Cepheids derived from NIR PW relations are essentially reduced to the intrinsic scatter of the adopted relations. Thus, the new templates are the ultimate tool for estimating precise Cepheid distances from NIR single-epoch observations, which can be safely adopted for future interesting applications, including deriving the 3D structure of the Magellanic Clouds.
- ID:
- ivo://CDS.VizieR/J/AJ/141/105
- Title:
- NIR-matched quasar catalog
- Short Name:
- J/AJ/141/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of over 130000 quasar candidates with near-infrared (NIR) photometric properties, with an areal coverage of approximately 1200deg^2^. This is achieved by matching the Sloan Digital Sky Survey (SDSS) in the optical ugriz bands to the UKIRT Infrared Digital Sky Survey (UKIDSS) Large Area Survey (LAS) in the NIR YJHK bands. We match the ~1 million SDSS DR6 Photometric Quasar catalog to Data Release 3 of the UKIDSS LAS (ULAS) and produce a catalog with 130827 objects with detections in one or more NIR bands, of which 74351 objects have optical and K-band detections and 42133 objects have the full nine-band photometry.
