- ID:
- ivo://CDS.VizieR/J/ApJ/752/42
- Title:
- BV time series in Ursa Major II
- Short Name:
- J/ApJ/752/42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a B, V color-magnitude diagram (CMD) of the Milky Way dwarf satellite Ursa Major II (UMa II), spanning the magnitude range from V~15 to V~23.5mag and extending over an 18x18 arcmin^2^ area centered on the Galaxy. Our photometry goes down to about 2 mag below the Galaxy's main-sequence turnoff that we detected at V~21.5 mag. We have discovered a bona fide RR Lyrae variable star in UMa II, which we use to estimate a conservative dereddened distance modulus for the galaxy of (m-M)_0_=17.70+/-0.04+/-0.12mag, where the first error accounts for the uncertainties of the calibrated photometry, and the second reflects our lack of information on the metallicity of the star. The corresponding distance to UMa II is 34.7^+0.6^_-0.7_(^+2.0^_-1.9_)kpc. Our photometry shows evidence of a spread in the Galaxy's subgiant branch, compatible with a spread in metal abundance in the range between Z=0.0001 and Z=0.001. Based on our estimate of the distance, a comparison of the fiducial lines of the Galactic globular clusters M68 and M5 ([Fe/H]=-2.27+/-0.04 dex and -1.33+/-0.02 dex, respectively), with the position on the CMD of spectroscopically confirmed Galaxy members, may suggest the existence of stellar populations of different metal abundance/age in the central region of UMa II.
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- ID:
- ivo://CDS.VizieR/J/PASJ/65/1
- Title:
- BX Dra BVR differential light curves
- Short Name:
- J/PASJ/65/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New CCD photometric observations of BX Dra were carried out on 26 nights during the period from 2009 April to 2010 June. The long-term photometric behaviors of the system are obtained from detailed studies of the period and light variations, based on historical data and our new observations.
- ID:
- ivo://CDS.VizieR/J/AJ/129/1642
- Title:
- Calibration of synthetic photometry
- Short Name:
- J/AJ/129/1642
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new calibration of optical (UBV, Stroemgren uvby{beta}, and Geneva) and near-IR (Johnson RIJHK and Two Micron All Sky Survey) photometry for B and early A stars derived from Kurucz ATLAS9 model atmospheres. These models are then used to calibrate the synthetic photometry.
- ID:
- ivo://CDS.VizieR/J/other/PASA/37.22
- Title:
- Calibration sample UBV and GALEX photometry
- Short Name:
- J/other/PASA/37.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive transformation equations between GALEX and UBV colours by using the reliable data of 556 stars. We present two sets of equations: as a function of (only) luminosity class and as a function of both luminosity class and metallicity. The metallicities are provided from the literature, while the luminosity classes are determined by using the PARSEC mass tracks in this study. Small colour residuals and high squared correlation coefficients promise accurate derived colours. The application of the transformation equations to 70 stars with reliable data shows that the metallicity plays an important role in estimation of more accurate colours.
- ID:
- ivo://CDS.VizieR/J/ApJS/206/10
- Title:
- CANDELS multiwavelength catalog
- Short Name:
- J/ApJS/206/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the multiwavelength ultraviolet to mid-infrared catalog of the UKIRT Infrared Deep Sky Survey (UKIDSS) Ultra-Deep Survey field observed as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). Based on publicly available data, the catalog includes the CANDELS data from the Hubble Space Telescope (near-infrared WFC3 F125W and F160W data and visible ACS F606W and F814W data); u-band data from CFHT/Megacam; B, V, Rc, i', and z' band data from Subaru/Suprime-Cam; Y and Ks band data from VLT/HAWK-I; J, H, and K band data from UKIDSS (Data Release 8); and Spitzer/IRAC data (3.6, 4.5um from SEDS; 5.8 and 8.0um from SpUDS). The present catalog is F160W-selected and contains 35932 sources over an area of 201.7arcmin^2^ and includes radio- and X-ray-detected sources and spectroscopic redshifts available for 210 sources.
- ID:
- ivo://CDS.VizieR/J/ApJS/229/32
- Title:
- CANDELS: multiwavelength catalogs in the EGS
- Short Name:
- J/ApJS/229/32
- Date:
- 03 Nov 2021 09:14:43
- Publisher:
- CDS
- Description:
- We present a 0.4-8{mu}m multi-wavelength photometric catalog in the Extended Groth Strip (EGS) field. This catalog is built on the Hubble Space Telescope (HST) WFC3 and ACS data from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), and it incorporates the existing HST data from the All-wavelength Extended Groth strip International Survey (AEGIS) and the 3D-HST program. The catalog is based on detections in the F160W band reaching a depth of F160W=26.62 AB (90% completeness, point sources). It includes the photometry for 41457 objects over an area of ~206arcmin^2^ in the following bands: HST/ACS F606W and F814W; HST WFC3 F125W, F140W, and F160W; Canada-France-Hawaii Telescope (CFHT)/Megacam u*, g' , r', i' and z'; CFHT/WIRCAM J, H, and K_S_; Mayall/NEWFIRM J1, J2, J3, H1, H2, and K; Spitzer IRAC 3.6, 4.5, 5.8, and 8.0{mu}m. We are also releasing value-added catalogs that provide robust photometric redshifts and stellar mass measurements.
- ID:
- ivo://CDS.VizieR/J/ApJ/816/L4
- Title:
- Candidate BHB stars in Ophiuchus stream
- Short Name:
- J/ApJ/816/L4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Ophiuchus stellar stream presents a dynamical puzzle: its old stellar populations (~12Gyr) cannot be reconciled with (1) its orbit in a simple model for the Milky Way potential and (2) its short angular extent, both of which imply that the observed stream formed within the last <1Gyr. Recent theoretical work has shown that streams on chaotic orbits may abruptly fan out near their apparent ends; stars in these fans are dispersed in both position and velocity and may be difficult to associate with the stream. Here we present the first evidence of such stream-fanning in the Ophiuchus stream, traced by four blue horizontal branch stars beyond the apparent end of the stream. These stars stand out from the background by their high velocities (v_los_>230km/s) against ~40 other stars: their velocities are comparable to those of the stream, but would be exceptional if they were unrelated halo stars. Their positions and velocities are, however, inconsistent with simple extrapolation of the observed cold, high-density portion of the stream. These observations suggest that stream-fanning may be a real, observable effect and, therefore, that Ophiuchus may be on a chaotic orbit. They also show that the Ophiuchus stream is more extended and hence dynamically older than previously thought, easing the stellar population versus dynamical age tension.
- ID:
- ivo://CDS.VizieR/J/ApJ/795/L26
- Title:
- Candidate eruptive young stars in Lynds 1340
- Short Name:
- J/ApJ/795/L26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the discovery of three candidate eruptive young stars, found during our comprehensive multi-wavelength study of the young stellar population of the dark cloud L1340. These stars are as follows. (1) IRAS 02224+7227 (2MASS 02270555+7241167, HH 487S) exhibited FUor-like spectrum in our low-resolution optical spectra. The available photometric data restrict its luminosity to 23L_{sun}_<L_bol_<59L_{sun}_. (2) 2MASS 02263797+7304575, identified as a classical T Tauri star during our H{alpha} survey, exhibited an EXor-type brightening in 2005 November at the time of the Sloan Digital Sky Survey observations of the region. (3) 2MASSJ02325605+7246055, a low-mass embedded young star, associated with a fan-shaped infrared nebula, underwent an outburst between the DSS 1 and DSS 2 surveys, leading to the appearance of a faint optical nebula. Our [SII] and H{alpha} images, as well as the Spitzer Infrared Array Camera 4.5{mu}m images, revealed Herbig-Haro objects associated with this star. Our results suggest that amplitudes and timescales of outbursts do not necessarily correlate with the evolutionary stage of the stars.
- ID:
- ivo://CDS.VizieR/J/AJ/149/78
- Title:
- Candidate IR variables from SAGE-SMC survey
- Short Name:
- J/AJ/149/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present our study on the infrared variability of point sources in the Small Magellanic Cloud (SMC). We use the data from the Spitzer Space Telescope Legacy Program "Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud" (SAGE-SMC) and the "Spitzer Survey of the Small Magellanic Cloud" (S^3^MC) survey, over three different epochs, separated by several months to 3 years. Variability in the thermal infrared is identified using a combination of Spitzer's InfraRed Array Camera 3.6, 4.5, 5.8, and 8.0{mu}m bands, and the Multiband Imaging Photometer for Spitzer 24{mu}m band. An error-weighted flux difference between each pair of three epochs ("variability index") is used to assess the variability of each source. A visual source inspection is used to validate the photometry and image quality. Out of ~2 million sources in the SAGE-SMC catalog, 814 meet our variability criteria. We matched the list of variable star candidates to the catalogs of SMC sources classified with other methods, available in the literature. Carbon-rich Asymptotic Giant Branch (AGB) stars make up the majority (61%) of our variable sources, with about a third of all of our sources being classified as extreme AGB stars. We find a small, but significant population of oxygen-rich (O-rich) AGB (8.6%), Red Supergiant (2.8%), and Red Giant Branch (<1%) stars. Other matches to the literature include Cepheid variable stars (8.6%), early type stars (2.8%), Young-stellar objects (5.8%), and background galaxies (1.2%). We found a candidate OH maser star, SSTISAGE1C J005212.88-730852.8, which is a variable O-rich AGB star, and would be the first OH/IR star in the SMC, if confirmed. We measured the infrared variability of a rare RV Tau variable (a post-AGB star) that has recently left the AGB phase. 59 variable stars from our list remain unclassified.
- ID:
- ivo://CDS.VizieR/J/ApJ/823/11
- Title:
- Candidate Ly{alpha} emitting galaxies at z~3.8
- Short Name:
- J/ApJ/823/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new observations of the field containing the z=3.786 protocluster PC 217.96+32.3. We confirm that it is one of the largest known and most overdense high-redshift structures. Such structures are rare even in the largest cosmological simulations. We used the Mayall/MOSAIC1.1 imaging camera to image a 1.2x0.6{deg} area (~150x75 comoving Mpc) surrounding the protocluster's core and discovered 165 candidate Ly{alpha} emitting galaxies (LAEs) and 788 candidate Lyman Break galaxies (LBGs). There are at least two overdense regions traced by the LAEs, the largest of which shows an areal overdensity in its core (i.e., within a radius of 2.5 comoving Mpc) of 14+/-7 relative to the average LAE spatial density (\bar{rho}) in the imaged field. Further, \bar{rho} is twice that derived by other field LAE surveys. Spectroscopy with Keck/DEIMOS yielded redshifts for 164 galaxies (79 LAEs and 85 LBGs); 65 lie at a redshift of 3.785+/-0.010. The velocity dispersion of galaxies near the core is {sigma}=350+/-40km/s, a value robust to selection effects. The overdensities are likely to collapse into systems with present-day masses of >10^15^M_{sun}_ and >6x10^14^M_{sun}_. The low velocity dispersion may suggest a dynamically young protocluster. We find a weak trend between narrow-band (Ly{alpha}) luminosity and environmental density: the Ly{alpha} luminosity is enhanced on average by 1.35x within the protocluster core. There is no evidence that the Ly{alpha} equivalent width depends on environment. These suggest that star formation and/or active galactic nucleus (AGN) activity is enhanced in the higher-density regions of the structure. PC 217.96+32.3 is a Coma cluster analog, witnessed in the process of formation.
