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Start Over Subject photometry Validation Level 2
7591. UV-upturn of elliptical galaxies model
ID:
ivo://CDS.VizieR/J/MNRAS/380/1098
Title:
UV-upturn of elliptical galaxies model
Short Name:
J/MNRAS/380/1098
Date:
21 Oct 2021
Publisher:
CDS
Description:
A long-standing problem in the study of elliptical galaxies is the far-ultraviolet (FUV) excess in their spectra (also known as UV-upturn, UV rising-branch, UV rising flux, or UVX). While it is now clear that this UV excess is caused by an old population of hot helium-burning stars without large hydrogen-rich envelopes. We have developed an evolutionary population synthesis (EPS) model for the FUV excess of elliptical galaxies based on the binary model of Han et al. (2002MNRAS.336..449H and 2003MNRAS.341..669H) for the formation of hot subdwarfs in our Galaxy. We give the colour evolution of a simple stellar population (SSP) (including binaries) of 10^10^M_{sun}_ for our standard simulation set. We have also compiled a file for the SED evolution, in which the SEDs without binary interactions are also supplied.
7592. UV variability and accretion in NGC 2264
ID:
ivo://CDS.VizieR/J/A+A/581/A66
Title:
UV variability and accretion in NGC 2264
Short Name:
J/A+A/581/A66
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photometric variability is a distinctive feature of young stellar objects; exploring variability signatures at different wavelengths provides insight into the physical processes at work in these sources. We explore the variability signatures at ultraviolet (UV) and optical wavelengths for several hundred accreting and non-accreting members of the star-forming region NGC 2264 (~3Myr).
7593. UV variability with GALEX gPhoton archive. I.
ID:
ivo://CDS.VizieR/J/ApJS/238/25
Title:
UV variability with GALEX gPhoton archive. I.
Short Name:
J/ApJS/238/25
Date:
21 Oct 2021
Publisher:
CDS
Description:
In order to develop and test a methodology to search for UV variability over the entire Galaxy Evolution Explorer (GALEX) database down to the shortest timescales, we analyzed time-domain photometry of ~5000 light curves of ~300 bright (mFUV, mNUV<=14) and blue (mFUV-mNUV<0) GALEX sources. Using the gPhoton database tool, we discovered and characterized instrumentally induced variabilities in time-resolved GALEX photometry that may severely impact automated searches for short-period variations. The most notable artifact is a quasi-sinusoidal variation mimicking light curves typical of pulsators, seen occasionally in either one or both detectors, with amplitudes of up to 0.3mag and periods corresponding to the periodicity of the spiral dithering pattern used during the observation (P~120s). Therefore, the artifact may arise from small-scale response variations. Other artifacts include visit-long "sagging" or "hump" in flux, occurring when the dithering pattern is not a spiral, or a one-time change in flux level during the exposure. These instrumentally caused variations were not reported before, and are not due to known (and flagged) artifacts such as hotspots, which can be easily eliminated. To characterize the frequency and causality of such artifacts, we apply Fourier transform analysis to both light curves and dithering patterns, and examine whether artificial brightness variations correlate with visit or instrumental parameters. Artifacts do not correlate with source position on the detector. We suggest methods to identify artifact variations and to correct them when possible.
7594. UV Variations in spectrum of Abell 35 c.star
ID:
ivo://CDS.VizieR/J/A+A/287/591
Title:
UV Variations in spectrum of Abell 35 c.star
Short Name:
J/A+A/287/591
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
7595. UV, VIH photometry of NGC 1311
ID:
ivo://CDS.VizieR/J/AJ/140/1137
Title:
UV, VIH photometry of NGC 1311
Short Name:
J/AJ/140/1137
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have extracted point-spread-function-fitted stellar photometry from near-ultraviolet, optical, and near-infrared images, obtained with the Hubble Space Telescope, of the nearby (D~5.5Mpc) SBm galaxy NGC 1311. The ultraviolet and optical data reveal a population of hot main-sequence (MS) stars with ages of 2-10Myr. We also find populations of blue supergiants with ages between 10 and 40Myr and red supergiants with ages between 10 and 100Myr.
7596. uz,vz,bz,yz photometry in Coma cluster
ID:
ivo://CDS.VizieR/J/AJ/124/3061
Title:
uz,vz,bz,yz photometry in Coma cluster
Short Name:
J/AJ/124/3061
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have observed three fields of the Coma Cluster of galaxies with a narrowband (modified Stroemgren) filter system. Observed galaxies include 31 in the vicinity of NGC 4889, 48 near NGC 4874, and 60 near NGC 4839, complete to M_5500_=-18 in all three subclusters. Spectrophotometric classification finds all three subclusters of Coma to be dominated by red, E-type (elliptical/S0) galaxies with a mean blue fraction, f_B_, of 0.10.
7597. Validated & new members of NGC 7000/IC 5070 Complex
ID:
ivo://CDS.VizieR/J/ApJ/899/128
Title:
Validated & new members of NGC 7000/IC 5070 Complex
Short Name:
J/ApJ/899/128
Date:
14 Mar 2022 07:05:45
Publisher:
CDS
Description:
We examine the clustering and kinematics of young stellar objects (YSOs) in the North America/Pelican Nebulae, as revealed by Gaia astrometry, in relation to the structure and motions of the molecular gas, as indicated in molecular-line maps. The Gaia parallaxes and proper motions allow us to significantly refine previously published lists of YSOs, demonstrating that many of the objects previously thought to form a distributed population turn out to be nonmembers. The members are subdivided into at least six spatio-kinematic groups, each of which is associated with its own molecular cloud component or components. Three of the groups are expanding, with velocity gradients of 0.3-0.5km/s/pc, up to maximum velocities of ~8km/s away from the groups' centers. The two known O-type stars associated with the region, 2MASS J20555125+4352246 and HD 199579, are rapidly escaping one of these groups, following the same position-velocity relation as the low-mass stars. We calculate that a combination of gas expulsion and tidal forces from the clumpy distribution of molecular gas could impart the observed velocity gradients within the groups. However, on a global scale, the relative motions of the groups do not appear either divergent or convergent. The velocity dispersion of the whole system is consistent with the kinetic energy gained due to gravitational collapse of the complex. Most of the stellar population has ages similar to the freefall timescales for the natal clouds. Thus, we suggest the nearly freefall collapse of a turbulent molecular cloud as the most likely scenario for star formation in this complex.
7598. 44 validated planets from K2 Campaign 10
ID:
ivo://CDS.VizieR/J/AJ/156/78
Title:
44 validated planets from K2 Campaign 10
Short Name:
J/AJ/156/78
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 44 validated planets from the 10th observing campaign of the NASA K2 mission, as well as high-resolution spectroscopy and speckle imaging follow-up observations. These 44 planets come from an initial set of 72 vetted candidates, which we subjected to a validation process incorporating pixel-level analyses, light curve analyses, observational constraints, and statistical false positive probabilities. Our validated planet sample has median values of R_p_=2.2 R_{Earth}_, P_orb_=6.9 days, T_eq_=890 K, and J=11.2 mag. Of particular interest are four ultra-short period planets (P_orb_~<1 day), 16 planets smaller than 2 R_{Earth}_, and two planets with large predicted amplitude atmospheric transmission features orbiting infrared-bright stars. We also present 27 planet candidates, most of which are likely to be real and worthy of further observations. Our validated planet sample includes 24 new discoveries and has enhanced the number of currently known super-Earths (R_p_~1-2 R_{Earth}_), sub-Neptunes (R_p_~2-4 R_{Earth}_), and sub-Saturns (R_p_~4-8 R_{Earth}_) orbiting bright stars (J=8-10 mag) by ~4%, ~17%, and ~11%, respectively.
7599. VANDAM survey of Orion protostars. II.
ID:
ivo://CDS.VizieR/J/ApJ/890/130
Title:
VANDAM survey of Orion protostars. II.
Short Name:
J/ApJ/890/130
Date:
07 Mar 2022 13:26:15
Publisher:
CDS
Description:
We have conducted a survey of 328 protostars in the Orion molecular clouds with the Atacama Large Millimeter/submillimeter Array at 0.87mm at a resolution of ~0.1" (40au), including observations with the Very Large Array at 9mm toward 148 protostars at a resolution of ~0.08" (32au). This is the largest multiwavelength survey of protostars at this resolution by an order of magnitude. We use the dust continuum emission at 0.87 and 9mm to measure the dust disk radii and masses toward the Class 0, Class I, and flat-spectrum protostars, characterizing the evolution of these disk properties in the protostellar phase. The mean dust disk radii for the Class 0, Class I, and flat-spectrum protostars are 44.9_-3.4_^+5.8^, 37.0_-3.0_^+4.9^, and 28.5_-2.3_^+3.7^au, respectively, and the mean protostellar dust disk masses are 25.9_-4.0_^+7.7^, 14.9_-2.2_^+3.8^, 11.6_-1.9_^+3.5^M_{Earth}_, respectively. The decrease in dust disk masses is expected from disk evolution and accretion, but the decrease in disk radii may point to the initial conditions of star formation not leading to the systematic growth of disk radii or that radial drift is keeping the dust disk sizes small. At least 146 protostellar disks (35% of 379 detected 0.87mm continuum sources plus 42 nondetections) have disk radii greater than 50au in our sample. These properties are not found to vary significantly between different regions within Orion. The protostellar dust disk mass distributions are systematically larger than those of Class II disks by a factor of >4, providing evidence that the cores of giant planets may need to at least begin their formation during the protostellar phase.
7600. V348 And and V572 Per: heliocentric minima and RVs
ID:
ivo://CDS.VizieR/J/AJ/158/95
Title:
V348 And and V572 Per: heliocentric minima and RVs
Short Name:
J/AJ/158/95
Date:
21 Oct 2021
Publisher:
CDS
Description:
The eclipsing binaries are still important objects for our understanding of the universe. Especially these ones located within the more complex multiple systems can help us solving the problem of their origin and subsequent evolution of these higher order multiples. Photometry and spectroscopy spanning over more than 25 yr were used for the first complete analysis of the two bright triple systems, namely V348 And and V572 Per. The light curves in photometric filters were combined together with the radial velocities and analyzed simultaneously, yielding the precise physical parameters of the eclipsing components of these multiple systems. The system V348 And consists of two eclipsing components with its orbital period of about 27.7 days. The system is a very detached one, and both eclipses are rather narrow, lasting only about 0.016 of its period. The visual orbit of the wide pair has the period of about 87 yr. All three components of the system are probably of B8-9 spectral type, and the parallax of the system was slightly shifted to the value of 2.92 mas. On the other hand, the system V572 Per shows apsidal motion of its inner orbit, the orbital period being of about 1.2 days, while the apsidal motion of about 48 yr. The components are of A and F spectral types, while the motion with the third component around a common barycenter is only negligible. According to our modeling, this system is not a member of open cluster Alpha Persei.