- ID:
- ivo://CDS.VizieR/J/A+A/499/47
- Title:
- Lick indices of EDCSN galaxies
- Short Name:
- J/A+A/499/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive analysis of the stellar population properties (age, metallicity and the alpha-element enhancement [E/Fe]) and morphologies of red-sequence galaxies in 24 clusters and groups from z~0.75 to z~0.45. The dataset, consisting of 215 spectra drawn from the ESO Distant Cluster Survey, constitutes the largest spectroscopic sample at these redshifts for which such an analysis has been conducted. Analysis reveals that the evolution of the stellar population properties of red-sequence galaxies depend on their mass: while the properties of most massive are well described by passive evolution and high-redshift formation, the less massive galaxies require a more extended star formation history. We show that these scenarios reproduce the index-sigma relations as well as the galaxy colours. The two main results of this work are (1) the evolution of the line-strength indices for the red-sequence galaxies can be reproduced if 40% of the galaxies with sigma<175km/s entered the red-sequence between z=0.75 to z=0.45, in agreement with the fraction derived in studies of the luminosity functions, and (2) the percentage of galaxies in the red-sequence with early-type morphologies (E/S0) decreases by 20% from z=0.75 to z=0.45. This can be understood if the red-sequence gets populated at later times with disc galaxies with quenched star formation. We conclude that the processes quenching star formation do not necessarily produce a simultaneous morphological transformation of the galaxies entering the red-sequence.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/143/14
- Title:
- Lick indices of M31 globular clusters
- Short Name:
- J/AJ/143/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present absorption line indices measured in the integrated spectra of globular clusters both from the Galaxy and from M31. Our samples include 41 Galactic globular clusters, and more than 300 clusters in M31. The conversion of instrumental equivalent widths into the Lick system is described, and zero-point uncertainties are provided. Comparison of line indices of old M31 clusters and Galactic globular clusters suggests an absence of important differences in chemical composition between the two cluster systems. In particular, CN indices in the spectra of M31 and Galactic clusters are essentially consistent with each other, in disagreement with several previous works. We reanalyze some of the previous data, and conclude that reported CN differences between M31 and Galactic clusters were mostly due to data calibration uncertainties. Our data support the conclusion that the chemical compositions of Milky Way and M31 globular clusters are not substantially different, and that there is no need to resort to enhanced nitrogen abundances to account for the optical spectra of M31 globular clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/141/53
- Title:
- Lick indices of type II Cepheid candidates
- Short Name:
- J/AJ/141/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present low-resolution spectra for variable stars in the Cepheid period range from the ROTSE-I Demonstration Project and the All Sky Automated Survey, some of which were previously identified as type II Cepheid candidates. We have derived effective temperatures, gravities, and metallicities from the spectra. Based on this, three types of variables were identified: Cepheid strip stars, cool stars that lie along the red subgiant and giant branch, and cool main-sequence stars. Many fewer type II Cepheids were found than expected and most have amplitudes less than 0.4mag. The cool variables include many likely binaries as well as intrinsic variables. Variation among the main-sequence stars is likely to be mostly due to binarity or stellar activity.
- ID:
- ivo://CDS.VizieR/J/ApJ/837/120
- Title:
- Lick Observatory Supernova Search (LOSS) revisited
- Short Name:
- J/ApJ/837/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most types of supernovae (SNe) have yet to be connected with their progenitor stellar systems. Here, we reanalyze the 10-year SN sample collected during 1998-2008 by the Lick Observatory Supernova Search (LOSS; see Leaman+, 2011, J/MNRAS/412/1419) in order to constrain the progenitors of SNe Ia and stripped-envelope SNe (SE SNe, i.e., SNe IIb, Ib, Ic, and broad-lined Ic). We matched the LOSS galaxy sample with spectroscopy from the Sloan Digital Sky Survey (SDSS) and measured SN rates as a function of galaxy stellar mass, specific star formation rate, and oxygen abundance (metallicity). We find significant correlations between the SN rates and all three galaxy properties. The SN Ia correlations are consistent with other measurements, as well as with our previous explanation of these measurements in the form of a combination of the SN Ia delay-time distribution and the correlation between galaxy mass and age. The ratio between the SE SN and SN II rates declines significantly in low-mass galaxies. This rules out single stars as SE SN progenitors, and is consistent with predictions from binary-system progenitor models. Using well-known galaxy scaling relations, any correlation between the rates and one of the galaxy properties examined here can be expressed as a correlation with the other two. These redundant correlations preclude us from establishing causality-that is, from ascertaining which of the galaxy properties (or their combination) is the physical driver for the difference between the SE SN and SN II rates. We outline several methods that have the potential to overcome this problem in future works.
- ID:
- ivo://CDS.VizieR/J/AJ/106/426
- Title:
- Lick slit spectra of quasar
- Short Name:
- J/AJ/106/426
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Lick Observatory slit spectra of 38 objects which were claimed to have pronounced ultraviolet excess and emission lines. Zhan & Chen (ZC) selected these objects by eye from a UK Schmidt telescope IIIaJ objective prism plate of a field at 0h 0.0deg (l ~= 98 deg, b ~= -60 deg). We concentrate on m(J) ~= 18-19 objects which Zhan and Chen (ZC) thought were most likely to be quasistellar objects (QSOs) at redshift z(em) >= 2.8. Most of our spectra have FWHM spectral resolutions of about 4 A, and relatively high S/N of about 10-50, although some have FWHM ~= 15 A or lower S/N. We find eleven QSOs, four galaxies at z ~= 0.1, twenty-two stars and one unidentified object with a low S/N spectrum. The ZC lists are found to contain many QSOs at low z but few at high z, as expected. Of eleven objects which ZC suggested were QSOs with z(prism) <= 2.8, eight (73%) are QSOs. But only three of twenty-five candidates with z(prism) >= 2.8 are QSOs, and only two (8%) of these are at z >= 2.8. Unfortunately, the ZC prism redshifts are often incorrect: only five of the eleven QSOs are at redshifts similar to z(prism). Six of the QSOs show absorption systems, including Q0000+027A with a relatively strong associated C IV absorption system, and Q0008+008 (V ~= 18.9) with a damped Ly alpha system with an HI column density of 10^21 cm^-2. The stars include a wide variety of spectral types. There is one new DA 4 white dwarf at 170 pc, one sdB at 14 kpc, and three M stars. The rest are of types F, G, and K. We have measured the equivalent widths of the Ca II K line, the G band, and the Balmer lines in ten stars with the best spectra, and we derive metallicities. Seven of them are in the range -2.5 <= [Fe/H] <= -1.7, while the others are less metal poor. If the stars are dwarfs, then they are at distances of 1 to 7 kpc, but if they are giants, typical distances will be about 10 kpc.
- 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.
- ID:
- ivo://CDS.VizieR/J/AJ/157/191
- Title:
- Light curve & radial velocities for TOI-172
- Short Name:
- J/AJ/157/191
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of TOI-172 b from the Transiting Exoplanet Survey Satellite (TESS) mission, a massive hot Jupiter transiting a slightly evolved G star with a 9.48-day orbital period. This is the first planet to be confirmed from analysis of only the TESS full frame images, because the host star was not chosen as a two-minute cadence target. From a global analysis of the TESS photometry and follow-up observations carried out by the TESS Follow-up Observing Program Working Group, TOI-172 (TIC 29857954) is a slightly evolved star with an effective temperature of T_eff_=5645+/-50 K, a mass of M_*_=1.128_-0.061_^+0.065^ M_{sun}_, radius of R_*_=1.777_-0.044_^+0.047^ R_{sun}_, a surface gravity of log g_*_=3.993_-0.028_^+0.027^, and an age of 7.4_-1.5_^+1.6^ Gyr. Its planetary companion (TOI-172 b) has a radius of R_P_=0.965_-0.029_^+0.032^ R_J_, a mass of M_P_=5.42_-0.20_^+0.22^ M_J_, and is on an eccentric orbit (e=0.3806_-0.0090_^+0.0093^). TOI-172 b is one of the few known massive giant planets on a highly eccentric short-period orbit. Future study of the atmosphere of this planet and its system architecture offer opportunities to understand the formation and evolution of similar systems.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A25
- Title:
- Light curves for the eclipsing binary V1094 Tau
- Short Name:
- J/A+A/578/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- V1094 Tau is a bright eclipsing binary star with an orbital period close to 9 days containing two stars similar to the Sun. Our aim is to test models of Sun-like stars using precise and accurate mass and radius measurements for both stars in V1094 Tau. We present new spectroscopy of V1094 Tau which we use to estimate the effective temperatures of both stars and to refine their spectroscopic orbits. We also present new, high-quality photometry covering both eclipses of V1094 Tau in the Stroemgren uvby system and in the Johnson V-band. The masses, radii and effective temperatures of the stars in V1094 Tau are found to be M_A_=1.0965+/-0.0040M_{sun}_, R_A_=1.4109+/-0.0058R_{sun}_, T_eff,A_=5850+/-100K, and M_B_=1.0120+/-0.0028M_{sun}_, R_B_=1.1063+/-0.0066R_{sun}_, T_eff,B_=5700+/-100K. An analysis of the times of mid-eclipse and the radial velocity data reveals apsidal motion with a period of 14500+/-3700-years. The observed masses, radii and effective temperatures are consistent with stellar models for an age ~6Gyr if the stars are assumed to have a metallicity similar to the Sun. This estimate is in reasonable agreement with our estimate of the metallicity derived using Stroemgren photometry and treating the binary as a single star ([Fe/H]=-0.09+/-0.11). The rotation velocities of the stars suggest that V1094 Tau is close to the limit at which tidal interactions between the stars force them to rotate pseudo-syncronously with the orbital motion.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A2
- Title:
- Light curves of DP CVn and DI Psc
- Short Name:
- J/A+A/551/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first Doppler imaging study of the two rapidly rotating, single K-giants DP CVn and DI Psc in order to study the surface spot configuration and to pinpoint their stellar evolutionary status. Optical spectroscopy and photometry are used to determine the fundamental astrophysical properties. Doppler imaging is applied to recover the surface temperature distribution for both stars, while photometric light-curve inversions are carried out for studying the long-term changes of the surface activity of DP CVn. Surface differential rotation of DP CVn is estimated from cross-correlating the available subsequent Doppler reconstructions separated by roughly one rotation period. Both stars appear to have higher than normal lithium abundance, LTE logn of 2.28 (DP CVn) and 2.20 (DI Psc), and are supposed to be located at the end of the first Li dredge-up on the RGB. Photometric observations reveal rotational modulation with a period of 14.010d (DP CVn) and 18.066d (DI Psc). Doppler reconstructions from the available mapping lines well agree in the revealed spot patterns, recovering rather low latitude spots for both stars with temperature contrasts of {DELTA}T~600-800K below the unspotted photospheric background. Spots at higher latitudes are also found but either with less contrast (DP CVn) or with smaller extent (DI Psc). A preliminary antisolar-type differential rotation with {alpha}=-0.035 is found for DP CVn from cross-correlating the subsequent Doppler images. Long-term photometric analysis supports the existence of active longitudes, as well as the differential rotation.
- ID:
- ivo://CDS.VizieR/J/A+A/524/A86
- Title:
- Light curves of SDSS J003941.06+005427.5
- Short Name:
- J/A+A/524/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present VLT spectroscopy and NTT photometry of the faint cataclysmic binary SDSS J003941.06+005427.5. This object shows triple-peaked H{alpha} emission with all three peaks variable in both strength and velocity. We measure an orbital period of 91.395+/-0.093min from the velocity variations of the wings of the Halpha emission line. Using the GALEX and SDSS photometry of this object, we determine a white dwarf temperature of 15000K and a very late (>=L2) spectral type for the companion star. These measurements, plus the relatively long orbital period, suggest that SDSS J003941.06+005427.5 may be a post-bounce cataclysmic variable. Doppler maps of the H{alpha} and HeI 6678{AA} emission features show an accretion disc with a non-uniform brightness and departures from Keplerian flow. The third emission peak is detected only in H{alpha} and at a relatively low velocity amplitude of 202+/-3km/s. We are unable to explain this emission as arising from either the white dwarf, the secondary star, or the accretion disc. We tentatively attribute this mysterious central peak to a coronal loop anchored at the secondary star. If confirmed, this would be the first example of a slingshot prominence in a CV with a low mass-transfer rate and/or a fully convective secondary star.
