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25161. z~0.8 quiescent galaxy kinematics from LEGA-C
ID:
ivo://CDS.VizieR/J/ApJ/858/60
Title:
z~0.8 quiescent galaxy kinematics from LEGA-C
Short Name:
J/ApJ/858/60
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present stellar rotation curves and velocity dispersion profiles for 104 quiescent galaxies at z=0.6-1 from the Large Early Galaxy Astrophysics Census (LEGA-C) spectroscopic survey. Rotation is typically probed across 10-20kpc, or to an average of 2.7Re. Combined with central stellar velocity dispersions ({sigma}0) this provides the first determination of the dynamical state of a sample selected by a lack of star formation activity at large lookback time. The most massive galaxies (M_*_>2x10^11^M_{sun}_) generally show no or little rotation measured at 5 kpc (|V_5_|/{sigma}_0_<0.2 in eight of ten cases), while ~64% of less massive galaxies show significant rotation. This is reminiscent of local fast- and slow- rotating ellipticals and implies that low- and high-redshift quiescent galaxies have qualitatively similar dynamical structures. We compare |V_5_|/{sigma}_0_ distributions at z~0.8 and the present day by re-binning and smoothing the kinematic maps of 91 low-redshift quiescent galaxies from the Calar Alto Legacy Integral Field Area (CALIFA) survey and find evidence for a decrease in rotational support since z~1. This result is especially strong when galaxies are compared at fixed velocity dispersion; if velocity dispersion does not evolve for individual galaxies then the rotational velocity at 5kpc was an average of 94+/-22% higher in z~0.8 quiescent galaxies than today. Considering that the number of quiescent galaxies grows with time and that new additions to the population descend from rotationally supported star-forming galaxies, our results imply that quiescent galaxies must lose angular momentum between z~1 and the present, presumably through dissipationless merging, and/or that the mechanism that transforms star-forming galaxies also reduces their rotational support.
25162. Zr, Ba, La, and Eu abundances in 19 open clusters
ID:
ivo://CDS.VizieR/J/AJ/145/107
Title:
Zr, Ba, La, and Eu abundances in 19 open clusters
Short Name:
J/AJ/145/107
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of the s-process elements Zr, Ba, and La and the r-process element Eu in a sample of 50 stars in 19 open clusters. Stellar abundances of each element are based on measures of a minimum of two lines per species via both equivalent width and spectrum synthesis techniques. We investigate cluster mean neutron-capture abundance trends as a function of cluster age and location in the Milky Way disk and compare them to results found in other studies in the literature. We find a statistically significant trend of increasing cluster [Ba/Fe] as a function of decreasing cluster age, in agreement with recent findings for other open cluster samples, supporting the increased importance of low-mass asymptotic giant branch stars to the generation of s-process elements. However, the other s-process elements, [La/Fe] and [Zr/Fe], do not show similar dependences, in contrast to theoretical expectations and the limited observational data from other studies. Conversely, cluster [Eu/Fe] ratios show a slight increase with increasing cluster age, although with marginal statistical significance. Ratios of [s/r]-process abundances, [Ba/Eu] and [La/Eu], however, show more clearly the increasing efficiency of s-process relative to r-process enrichment in open cluster chemical evolution, with significant increases among younger clusters. Last, cluster neutron-capture element abundances appear to be independent of Galactocentric distance. We conclude that a homogeneous analysis of a larger sample of open clusters is needed to resolve the apparent discrepant conclusions between different studies regarding s-process element abundance trends with age to better inform models of galactic chemical evolution.
25163. Zr II & III electron-impact broadening parameters
ID:
ivo://CDS.VizieR/J/A+A/365/656
Title:
Zr II & III electron-impact broadening parameters
Short Name:
J/A+A/365/656
Date:
21 Oct 2021
Publisher:
CDS
Description:
The electron-impact widths for 30 Zr III lines were calculated using the modified semi-empirical (MSE) method. For two Zr II and four Zr III astrophysically important UV lines, only electron-impact widths are given, since for their calculation the experimental oscillator strengths were used and consequently the accuracy of the parameters is lower than in the case of other lines. The influence of the electron-impact mechanism on line shapes and equivalent widths in hot star atmospheres was also considered. The impact of the electron-impact broadening effect on abundance determination, particularly its effect on "zirconium conflict" is discussed as well.
25164. Zr III transition data
ID:
ivo://CDS.VizieR/J/A+A/637/A10
Title:
Zr III transition data
Short Name:
J/A+A/637/A10
Date:
21 Oct 2021
Publisher:
CDS
Description:
We seek to present accurate and extensive transition data for the ZrIII ion. These data are useful in many astrophysical applications. We used the multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction (RCI) methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2018. The transverse-photon (Breit) interaction, vacuum polarization, and self-energy corrections are included in the RCI computations. Energy spectra were calculated for the 88 lowest states in the ZrIII ion. The root-mean-square deviation obtained in this study for computed energy spectra from the experimental data is 450cm^-1^. Electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transition data, line strengths, weighted oscillator strengths, and transition rates are computed between the above states together with the corresponding lifetimes. The computed transition rates are smaller than the experimental rates and the disagreement for weaker transitions is much larger than the experimental error bars. The computed lifetimes agree with available experimental values within the experimental uncertainties.
25165. z<0.4 sources from Chandra/SDSS
ID:
ivo://CDS.VizieR/J/ApJ/778/188
Title:
z<0.4 sources from Chandra/SDSS
Short Name:
J/ApJ/778/188
Date:
21 Oct 2021
Publisher:
CDS
Description:
Striking similarities have been seen between accretion signatures of Galactic X-ray binary (XRB) systems and active galactic nuclei (AGNs). XRB spectral states show a V-shaped correlation between X-ray spectral hardness and Eddington ratio as they vary, and some AGN samples reveal a similar trend, implying analogous processes at vastly larger masses and timescales. To further investigate the analogies, we have matched 617 sources from the Chandra Source Catalog (CSC) to Sloan Digital Sky Survey (SDSS) spectroscopy, and uniformly measured both X-ray and optical spectral characteristics across a broad range of AGN and galaxy types. We provide useful tabulations of X-ray spectral slope for broad- and narrow-line AGNs, star-forming and passive galaxies, and composite systems, also updating relationships between optical (H{alpha} and [OIII]) line emission and X-ray luminosity. We further fit broadband spectral energy distributions with a variety of templates to estimate bolometric luminosity. Our results confirm a significant trend in AGNs between X-ray spectral hardness and Eddington ratio expressed in X-ray luminosity, albeit with significant dispersion. The trend is not significant when expressed in the full bolometric or template-estimated AGN luminosity. We also confirm a relationship between the X-ray/optical spectral slope {alpha}_ox_ and Eddington ratio, but it may not follow the trend predicted by analogy with XRB accretion states.
25166. z~1 star-forming galaxies catalog
ID:
ivo://CDS.VizieR/J/MNRAS/503/1753
Title:
z~1 star-forming galaxies catalog
Short Name:
J/MNRAS/503/1753
Date:
02 Feb 2022 09:53:58
Publisher:
CDS
Description:
We investigate the shape of the rotation curves (RCs) of z~1 star-forming galaxies (SFGs) and compare them with local SFGs. For this purpose, we have used 344 galaxies from the K-band Multi-Object Spectrograph (KMOS) for Redshift One Spectroscopic Survey (KROSS). This sample covers the redshift range 0.57<=z<=1.04, the effective radii 0.69<=R_e_[kpc]<=7.76, and the stellar masses 8.7<=log(M_*_[M_{sun}_])<=11.32. Using ^3D^BAROLO, we extract the H {alpha} kinematic maps and corresponding RCs. The main advantage of ^3D^BAROLO is that it incorporates the beam smearing in the 3D observational space, which provide us with the intrinsic rotation velocity even in the low spatial resolution data. We have corrected the RCs for pressure support, which seems to be a more dominant effect than beam smearing in high-z galaxies. Only a combination of the three techniques (3D-kinematic modelling + 3D-beam smearing correction + pressure gradient correction) yields the intrinsic RC of an individual galaxy. Further, we present the co-added and binned RCs constructed out of 256 high-quality objects. We do not see any change in the shape of RCs with respect to the local SFGs. Moreover, we notice a significant evolution in the stellar-disc length (R_D_) of the galaxies as a function of their circular velocity. Therefore, we conclude that the stellar disc of SFGs evolves over cosmic time (from z~1) while the total mass stays constant (within ~20kpc).
25167. z~3.3 star-forming galaxies NIR spectra
ID:
ivo://CDS.VizieR/J/ApJ/822/42
Title:
z~3.3 star-forming galaxies NIR spectra
Short Name:
J/ApJ/822/42
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the relationship between stellar mass, star formation rate (SFR), ionization state, and gas-phase metallicity for a sample of 41 normal star-forming galaxies at 3<~z<~3.7. The gas-phase oxygen abundance, ionization parameter, and electron density of ionized gas are derived from rest-frame optical strong emission lines measured on near-infrared spectra obtained with Keck/Multi-Object Spectrograph for Infra-Red Exploration. We remove the effect of these strong emission lines in the broadband fluxes to compute stellar masses via spectral energy distribution fitting, while the SFR is derived from the dust-corrected ultraviolet luminosity. The ionization parameter is weakly correlated with the specific SFR, but otherwise the ionization parameter and electron density do not correlate with other global galaxy properties such as stellar mass, SFR, and metallicity. The mass-metallicity relation (MZR) at z~3.3 shows lower metallicity by ~0.7dex than that at z=0 at the same stellar mass. Our sample shows an offset by ~0.3dex from the locally defined mass-metallicity-SFR relation, indicating that simply extrapolating such a relation to higher redshift may predict an incorrect evolution of MZR. Furthermore, within the uncertainties we find no SFR-metallicity correlation, suggesting a less important role of SFR in controlling the metallicity at high redshift. We finally investigate the redshift evolution of the MZR by using the model by Lilly et al. (2013ApJ...772..119L), finding that the observed evolution from z=0 to z~3.3 can be accounted for by the model assuming a weak redshift evolution of the star formation efficiency.
25168. z>4 submillimeter galaxies
ID:
ivo://CDS.VizieR/J/ApJ/712/942
Title:
z>4 submillimeter galaxies
Short Name:
J/ApJ/712/942
Date:
21 Oct 2021
Publisher:
CDS
Description:
The existence of submillimeter-selected galaxies (SMGs) at redshifts z>4 has recently been confirmed. Simultaneously using all the available data from UV to radio, we have modeled the spectral energy distributions of the six known spectroscopically confirmed SMGs at z>4. We find that their star formation rates (average ~2500M_{sun}_/yr), stellar (~3.6x10^11^M_{sun}_) and dust (~6.7x10^8^M_{sun}_) masses, extinction (A_V_~2.2mag), and gas-to-dust ratios (~60) are within the ranges for 1.7<z<3.6 SMGs. Our analysis suggests that infrared-to-radio luminosity ratios of SMGs do not change up to redshift ~5 and are lower by a factor of ~2.1 than the value corresponding to the local IR-radio correlation. However, we also find dissimilarities between z>4 and lower-redshift SMGs. Those at z>4 tend to be among the most star-forming, least massive, and hottest (~60K) SMGs and exhibit the highest fraction of stellar mass formed in the ongoing starburst (~45%).
25169. ZTF early observations of Type Ia SNe. I. LCs
ID:
ivo://CDS.VizieR/J/ApJ/886/152
Title:
ZTF early observations of Type Ia SNe. I. LCs
Short Name:
J/ApJ/886/152
Date:
21 Oct 2021
Publisher:
CDS
Description:
Early-time observations of Type Ia supernovae (SNe Ia) are essential to constrain the properties of their progenitors. In this paper, we present high-quality light curves of 127 SNe Ia discovered by the Zwicky Transient Facility (ZTF) in 2018. We describe our method to perform forced point-spread function photometry, which can be applied to other types of extragalactic transients. With a planned cadence of six observations per night (three g + three r), all of the 127 SNe Ia are detected in both g and r bands more than 10 days (in the rest frame) prior to the epoch of g-band maximum light. The redshifts of these objects range from z=0.0181 to 0.165; the median redshift is 0.074. Among the 127 SNe, 50 are detected at least 14 days prior to maximum light (in the rest frame), with a subset of nine objects being detected more than 17 days before g-band peak. This is the largest sample of young SNe Ia collected to date; it can be used to study the shape and color evolution of the rising light curves in unprecedented detail. We discuss six peculiar events in this sample: one 02cx-like event ZTF18abclfee (SN2018crl), one Ia-CSM SN ZTF18aaykjei (SN2018cxk), and four objects with possible super-Chandrasekhar mass progenitors: ZTF18abhpgje (SN2018eul), ZTF18abdpvnd (SN2018dvf), ZTF18aawpcel (SN2018cir), and ZTF18abddmrf (SN2018dsx).
25170. ZTF light curve of 51 stars in 12 globular clusters
ID:
ivo://CDS.VizieR/J/AJ/162/63
Title:
ZTF light curve of 51 stars in 12 globular clusters
Short Name:
J/AJ/162/63
Date:
21 Mar 2022 11:55:52
Publisher:
CDS
Description:
In this work, we aimed to derive the gri-band period-luminosity (PL) and period-luminosity-color (PLC) relations for late-type contact binaries, for the first time, located in globular clusters, using the homogeneous light curves collected by the Zwicky Transient Factory (ZTF). We started with 79 contact binaries in 15 globular clusters, and retained 30 contact binaries in 10 globular clusters that have adequate numbers of data points in the ZTF light curves and are unaffected by blending. Magnitudes at mean and maximum light of these contact binaries were determined using a fourth-order Fourier expansion, while extinction corrections were done using the Bayerstar2019 3D reddening map together with adopting the homogeneous distances to their host globular clusters. After removing early-type and "anomaly" contact binaries, our derived gri-band PL and period-Wesenheit (PW) relations exhibited a much larger dispersion with large errors on the fitted coefficients. Nevertheless, the gr-band PL and PW relations based on this small sample of contact binaries in globular clusters were consistent with those based on a larger sample of nearby contact binaries. Good agreements of the PL and PW relations suggested both samples of contact binaries in the local Solar neighborhood and in the distant globular clusters can be combined and used to derive and calibrate the PL, PW, and PLC relations. The final derived gr-band PL, PW, and PLC relations were much improved over those based on the limited sample of contact binaries in the globular clusters.

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