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1891. LEGUS galaxies1 observations
ID:
ivo://CDS.VizieR/J/ApJS/235/23
Title:
LEGUS galaxies1 observations
Short Name:
J/ApJS/235/23
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle 21 Treasury program on the Hubble Space Telescope. It studied 50 nearby star-forming galaxies in 5 bands from the near-UV to the I-band, combining new Wide Field Camera 3 observations with archival Advanced Camera for Surveys data. LEGUS was designed to investigate how star formation occurs and develops on both small and large scales, and how it relates to the galactic environments. In this paper we present the photometric catalogs for all the apparently single stars identified in the 50 LEGUS galaxies. We present optical and near-UV color-magnitude diagrams for all the galaxies. For each galaxy we derived the distance from the tip of the red giant branch. We then used the NUV color-magnitude diagrams to identify stars more massive than 14M_{sun}_, and compared their number with the number of massive stars expected from the GALEX FUV luminosity. Our analysis shows that the fraction of massive stars forming in star clusters and stellar associations is about constant with the star formation rate. This lack of a relation suggests that the timescale for evaporation of unbound structures is comparable or longer than 10Myr. At low star formation rates this translates to an excess of mass in clustered environments as compared to model predictions of cluster evolution, suggesting that a significant fraction of stars form in unbound systems.
1892. LEGUS & Ha-LEGUS obs. of NGC4449 star clusters
ID:
ivo://CDS.VizieR/J/ApJ/889/154
Title:
LEGUS & Ha-LEGUS obs. of NGC4449 star clusters
Short Name:
J/ApJ/889/154
Date:
17 Jan 2022 11:55:48
Publisher:
CDS
Description:
We present a new catalog and results for the cluster system of the starburst galaxy NGC 4449, based on multiband imaging observations taken as part of the LEGUS and H_{alpha}_-LEGUS surveys. We improve the spectral energy fitting method used to estimate cluster ages, and find that the results, particularly for older clusters, are in better agreement with those from spectroscopy. The inclusion of H{alpha} measurements, the role of stochasticity for low-mass clusters, the assumptions about reddening, and the choices of SSP model and metallicity all have important impacts on the age dating of clusters. A comparison with ages derived from stellar color-magnitude diagrams for partially resolved clusters shows reasonable agreement, but large scatter in some cases. The fraction of light found in clusters relative to the total light (i.e., T_L_) in the U, B, and V filters in 25 different ~kiloparsec-size regions throughout NGC 4449 correlates with both the specific region luminosity, R_L_, and the dominant age of the underlying stellar population in each region. The observed cluster age distribution is found to decline over time as dN/d{tau}{propto}{tau}^{gamma}^, with {gamma}=-0.85+/-0.15, independent of cluster mass, and is consistent with strong, early cluster disruption. The mass functions of the clusters can be described by a power law with dN/dM{propto}M^{beta}^ and {beta}=-1.86+/-0.2, independent of cluster age. The mass and age distributions are quite resilient to differences in age-dating methods. There is tentative evidence for a factor of 2-3 enhancement in both the star and cluster formation rate ~100-300Myr ago, indicating that cluster formation tracks star formation generally. The enhancement is probably associated with an earlier interaction event.
1893. Leo IV g- and r-band photometry
ID:
ivo://CDS.VizieR/J/ApJ/718/530
Title:
Leo IV g- and r-band photometry
Short Name:
J/ApJ/718/530
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present MMT/Megacam imaging of the Leo IV dwarf galaxy in order to investigate its structure and star formation history, and to search for signs of association with the recently discovered Leo V satellite. Based on parameterized fits, we find that Leo IV is round, with {epsilon}<0.23 (at the 68% confidence limit) and a half-light radius of r_h_~130pc. Additionally, we perform a thorough search for extended structures in the plane of the sky and along the line of sight. We derive our surface brightness detection limit by implanting fake structures into our catalog with stellar populations identical to that of Leo IV. We show that we are sensitive to stream-like structures with surface brightness {mu}_r_<~29.6mag/arcsec^2^, and at this limit we find no stellar bridge between Leo IV (out to a radius of ~0.5kpc) and the recently discovered, nearby satellite Leo V. Using the color-magnitude fitting package StarFISH, we determine that Leo IV is consistent with a single age (~14Gyr), single metallicity ([Fe/H]~-2.3) stellar population, although we cannot rule out a significant spread in these values. We derive a luminosity of M_V_=-5.5+/-0.3. Studying both the spatial distribution and frequency of Leo IV's "blue plume" stars reveals evidence for a young (~2Gyr) stellar population which makes up ~2% of its stellar mass.
1894. Leo I VI photometry
ID:
ivo://CDS.VizieR/J/MNRAS/354/708
Title:
Leo I VI photometry
Short Name:
J/MNRAS/354/708
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present V and I photometry of a 9.4'x9.4' field centered on the dwarf spheroidal galaxy Leo I. The I magnitude of the tip of the Red Giant Branch is robustly estimated from two different datasets I^TRGB^=17.97 (^+0.05^_-0.03_). From this estimate, adopting [M/H]~-1.2 from the comparison of RGB stars with Galactic templates, we obtain a distance modulus (m-M)_0=22.02+/-0.13, corresponding to a distance D=254^+16^_-19_kpc.
1895. LHS faint proper-motion stars
ID:
ivo://CDS.VizieR/J/PASP/117/676
Title:
LHS faint proper-motion stars
Short Name:
J/PASP/117/676
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present low-resolution spectroscopic observations of faint proper-motion stars from the LHS Catalogue, concentrating on stars with m_r_>16.5 and {mu}>0.5"/yr. The present paper includes observations and spectral classifications for 294 M dwarfs, M subdwarfs (sdM), and extreme M subdwarfs (esdM). We also identify white dwarfs among the faintest LHS stars. We have cross-referenced this sample against the Two Micron All Sky Survey (2MASS) sources, and list data for the detected objects. We discuss stars of individual interest, as well as the characteristics of the overall sample. As expected, a significant number of the stars in this proper-motion-selected sample are halo subdwarfs, including an esdM dwarf, LHS 3481, that is likely to lie within 20pc of the Sun. None of the subdwarfs show H{alpha} emission.
1896. LH 47 UVBRI photometry
ID:
ivo://CDS.VizieR/J/A+AS/123/455
Title:
LH 47 UVBRI photometry
Short Name:
J/A+AS/123/455
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table 3 lists the final photometric data of our observations. The UBVRI observations were done with the 1.54m Danish telescope at ESO on October 3rd and 4th, 1992. The CCD was ESO#28, a TEK 1024x1024 with a pixel size of 24mue corresponding to 0.377" per pixel. The total field of view is 6.4'x6.4'. A standard reduction was done with MIDAS and IRAF, the photometry was performed with DAOPHOT within IRAF. The images of Oct 4th have been calibrated using the calibration field around PG 0231+051 (Landolt 1992, Cat. <II/183>). The images of Oct 3rd have then been adopted to the system of Oct 4th. The final Table 3 lists 4613 stars with V and B-V information. In addition U-B is available for 1159 of these stars, V-R for 3519 and V-I for 2854 stars. Table 4 gives those stars from our field of view which are present in the MACS (Magellanic Catalogue of Stars; Tucholke et al. 1996, Cat. <I/221>). The table contains the MACS Id., our x and y position and our UBV photometry, and right ascension and declination from the MACS. These stars may serve to calculate an exact position for every star from Table 3 or to define a coordinate grid for comparison with other observations, such as radio or X-ray data.
1897. Library of Spectra (0.5 to 2.5um) of Cool Stars
ID:
ivo://CDS.VizieR/J/A+AS/146/217
Title:
Library of Spectra (0.5 to 2.5um) of Cool Stars
Short Name:
J/A+AS/146/217
Date:
21 Oct 2021
Publisher:
CDS
Description:
The present catalogue contains 182 low resolution optical spectra, 145 medium resolution (R~1100) near-IR spectra, and 112 merged optical+near-IR spectra that range from about 510 to 2450 nm. The observed stars are luminous cool objects: the sample includes red giants, red supergiants, oxygen rich and carbon rich long period variables (asymptotic giant branch stars), as well as a few Galactic Bulge and LMC/SMC stars. The optical data were acquired on the so-called 74 inch Telescope at Mount Stromlo Observatory. The near-IR data were acquired with the Cryogenic Array Spectrometer and Imager CASPIR on the 2.3 meter Australian National University Telescope at Siding Spring Observatory. Optical and near-IR data for variable objects have been merged only when both were taken less than 15 days apart; but both spectral ranges are also provided separately. The spectra are corrected for telluric absorption. However, in regions where the transmission of the Earth atmosphere is close to zero the fluxes recovered remain highly uncertain. The flux calibration is based on a series of reference stars, for which a theoretical intrinsic energy distribution was assumed. An absolute flux calibration (to about 10% accuracy) was only achieved in exceptional cases; in the other cases, the absolute fluxes can be off their real values by an order of magnitude due to slit losses (for the programme star and/or the reference star) and to non-photometric wheather. Uncertainties in the relative values of fluxes along each spectrum are described in the paper.
1898. Li, C and O abundances of FGK stars
ID:
ivo://CDS.VizieR/J/AJ/159/90
Title:
Li, C and O abundances of FGK stars
Short Name:
J/AJ/159/90
Date:
21 Oct 2021
Publisher:
CDS
Description:
Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the Vilnius University Echelle Spectrograph (VUES) at the Moletai Astronomical Observatory of Vilnius University. The sample stars have metallicities, effective temperatures, and ages between -0.7-0.4dex, 5000-6900K, 1-12Gyr, accordingly. We confirm a so far unexplained lithium abundance decrease at supersolar metallicities --A(Li) in our sample stars, which drop by 0.7dex in the [Fe/H] range from +0.10 to +0.55dex. Furthermore, we identified stars with similar ages, atmospheric parameters, and rotational velocities, but with significantly different lithium abundances, which suggests that additional specific evolutionary factors should be taken into account while interpreting the stellar lithium content. Nine stars with predominantly supersolar metallicities, i.e., about 12% among 78 stars with C and O abundances determined, have the C/O number ratios larger than 0.65, thus may form carbon-rich rocky planets. Ten planet-hosting stars, available in our sample, do not show a discernible difference from the stars with no planets detected regarding their lithium content.
1899. Lick AGN monitoring project 2011: V band
ID:
ivo://CDS.VizieR/J/ApJ/871/108
Title:
Lick AGN monitoring project 2011: V band
Short Name:
J/ApJ/871/108
Date:
21 Oct 2021
Publisher:
CDS
Description:
In Spring 2011, the Lick AGN Monitoring Project observed a sample of 15 bright, nearby Seyfert 1 galaxies in the V band as part of a reverberation mapping campaign. The observations were taken at six ground-based telescopes, including the West Mountain Observatory 0.91m telescope, the 0.76m Katzman Automatic Imaging Telescope, 0.6m Super-LOTIS (Livermore Optical Transient Imaging System) at Kitt Peak, the Palomar 60inch telescope, and the 2m Faulkes telescopes North and South. The V-band light curves measure the continuum variability of our sample of Seyferts on an almost daily cadence for 2-3 months. We use image-subtraction software to isolate the variability of the Seyfert nucleus from the constant V-band flux of the host galaxy for the most promising targets, and we adopt standard aperture photometry techniques for the targets with smaller levels of variability. These V-band light curves will be used, with measurements of the broad emission line flux, to measure supermassive black hole masses and to constrain the geometry and dynamics of the broad-line region through dynamical modeling techniques.
1900. Light curve and radial velocities for 7 host stars
ID:
ivo://CDS.VizieR/J/AJ/162/7
Title:
Light curve and radial velocities for 7 host stars
Short Name:
J/AJ/162/7
Date:
18 Mar 2022 09:35:03
Publisher:
CDS
Description:
We report the discovery and characterization of seven transiting exoplanets from the HATNet survey. The planets, which are hot Jupiters and Saturns transiting bright Sun-like stars, include: HAT-P-58b (with mass M_p_=0.37M_J_, radius R_p_=1.33R_J_, and orbital period P=4.0138days), HAT-P-59b (M_p_=1.54M_J_, R_p_=1.12R_J_, P=4.1420days), HAT-P-60b (M_p_=0.57M_J_, R_p_=1.63R_J_, P=4.7948days), HAT-P-61b (M_p_=1.06M_J_, R_p_=0.90R_J_, P=1.9023days), HAT-P-62b (M_p_=0.76M_J_, R_p_=1.07R_J_, P=2.6453days), HAT-P-63b (M_p_=0.61M_J_, R_p_=1.12R_J_, P=3.3777days), and HAT-P-64b (M_p_=0.58M_J_, R_p_= 1.70R_J_, P=4.0072days). The typical errors on these quantities are 0.06M_J_, 0.03R_J_, and 0.2s, respectively. We also provide accurate stellar parameters for each of the host stars. With V=9.710{+/-}0.050mag, HAT-P-60 is an especially bright transiting planet host, and an excellent target for additional follow-up observations. With R_p_=1.703{+/-}0.070R_J_, HAT-P-64b is a highly inflated hot Jupiter around a star nearing the end of its main-sequence lifetime, and is among the largest known planets. Five of the seven systems have long-cadence observations by TESS which are included in the analysis. Of particular note is HAT-P-59 (TOI-1826.01) which is within the northern continuous viewing zone of the TESS mission, and HAT-P-60, which is the TESS candidate TOI-1580.01.