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2881. IK photometry of faint Extremely Red Objects
ID:
ivo://CDS.VizieR/J/MNRAS/346/1125
Title:
IK photometry of faint Extremely Red Objects
Short Name:
J/MNRAS/346/1125
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results from a survey for extremely red objects (EROs) in deep, high-resolution optical images taken from the Hubble Space Telescope (HST) Medium Deep Survey. We have surveyed 35 deep F814W HST/WFPC2 fields in the near-infrared to a typical depth of K>20. From a total area of 206 arcmin^2^ and to a limit of K=20.0, we identify 224 EROs [(1.14+/-0.08)arcmin^-2^] with (I_814_-K)>=4.0 and 83 [(0.41+/-0.05)arcmin^-2^] with (I_814_-K)>=5.0.
2882. i light curve ans spectra of Hen2-11 central star
ID:
ivo://CDS.VizieR/J/A+A/562/A89
Title:
i light curve ans spectra of Hen2-11 central star
Short Name:
J/A+A/562/A89
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a detailed photometric study of the central star system of the planetary nebula Hen 2-11, selected for study because of its low-ionisation filaments and bipolar morphology - traits which have been strongly linked with central star binarity. Photometric monitoring with NTT-EFOSC2 reveals a highly irradiated, double-eclipsing, post-common-envelope system with a period of 0.609 d. Modelling of the lightcurve indicates that the nebular progenitor is extremely hot, while the secondary in the system is probably a K-type main sequence star. The chemical composition of the nebula is analysed, showing Hen 2-11 to be a medium-excitation non-Type I nebula. A simple photoionisation model is constructed determining abundance ratios of C/O and N/O which would be consistent with the common-envelope cutting short the AGB evolution of the nebular progenitor. The detection of a post-common-envelope binary system at the heart of Hen 2-11 further strengthens the link between binary progeny and the formation of axisymmetric planetary nebulae with patterns of low-ionisation filaments, clearly demonstrating their use as morphological indicators of central star binarity.
2883. I light curves of RR Lyrae from OGLE II
ID:
ivo://CDS.VizieR/J/other/PZP/9.5
Title:
I light curves of RR Lyrae from OGLE II
Short Name:
J/other/PZP/9.5
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the discovery of ten RR Lyrae variables. They were found in a search for new variables in the OGLE II Photometric Database (Szymanski 2005AcA....55...43S, Udalski et al. 1997AcA....47..319U). Suitable parameters (e.g. Isig>0.1, e_Imed<Isig) were used in the OGLE Photometry Database Query Page (http://ogledb.astrouw.edu.pl/~ogle/photdb/) for stars in the Galactic Disk. Period analysis was made with the software AVE (GEA).
2884. 5 ILRTs light curves and spectra
ID:
ivo://CDS.VizieR/J/A+A/654/A157
Title:
5 ILRTs light curves and spectra
Short Name:
J/A+A/654/A157
Date:
07 Mar 2022 07:10:34
Publisher:
CDS
Description:
We present the spectroscopic and photometric study of five intermediate-luminosity red transients (ILRTs), namely AT 2010dn, AT 2012jc, AT 2013la, AT 2013lb, and AT 2018aes. They share common observational properties and belong to a family of objects similar to the prototypical ILRT SN 2008S. These events have a rise time that is less than 15 days and absolute peak magnitudes of between -11:5 and -14:5mag. Their pseudo-bolometric light curves peak in the range 0.5-9.0*10^40^erg/s and their total radiated energies are on the order of (0.3-3)*10^47^erg. After maximum brightness, the light curves show a monotonic decline or a plateau, resembling those of faint supernovae IIL or IIP, respectively. At late phases, the light curves flatten, roughly following the slope of the ^56^Co decay. If the late-time power source is indeed radioactive decay, these transients produce ^56^Ni masses on the order of 10^-4^ to 10^-3^M_{sun}_. The spectral energy distribution of our ILRT sample, extending from the optical to the mid-infrared (MIR) domain, reveals a clear IR excess soon after explosion and non-negligible MIR emission at very late phases. The spectra show prominent H lines in emission with a typical velocity of a few hundred km/s, along with CaII features. In particular, the [CaII]7291,7324 doublet is visible at all times, which is a characteristic feature for this family of transients. The identified progenitor of SN 2008S, which is luminous in archival Spitzer MIR images, suggests an intermediate-mass precursor star embedded in a dusty cocoon. We propose the explosion of a super-asymptotic giant branch star forming an electron-capture supernova as a plausible explanation for these events.
2885. Images of two DQ white dwarfs
ID:
ivo://CDS.VizieR/J/A+A/544/L6
Title:
Images of two DQ white dwarfs
Short Name:
J/A+A/544/L6
Date:
21 Oct 2021
Publisher:
CDS
Description:
The intensity profiles of the C2 Swan bands in cool DQ white dwarfs cannot be adequately fitted with models that otherwise succesfully reproduce spectral features of the molecule CH in these stars. Initial modelling showed that a two-component atmosphere in the style of a spot might be able to solve the problem. We photometrically observed the two cool DQ white dwarfs GJ1117 and EGGR78 to search for variability caused by stellar spots. We have not found any such variability, but we estimate the effects of hypothetical spots on lightcurves. We also estimate detection probabilities for spots in different configurations. Alternative explanations of the problem are needed and briefly discussed.
2886. Images of Vega at 1.3mm
ID:
ivo://CDS.VizieR/J/A+A/531/L2
Title:
Images of Vega at 1.3mm
Short Name:
J/A+A/531/L2
Date:
21 Oct 2021
Publisher:
CDS
Description:
Previous studies have found that Vega is surrounded by an extended debris disc that is very smooth in the far infrared, but displays possible clumpiness at 850um and dust emission peaks at 1.3mm. We reobserved Vega at 1.3mm with PdBI to constrain its circumstellar dust distribution.
2887. Imaging and spectroscopy around PKS 0405-123
ID:
ivo://CDS.VizieR/J/ApJ/643/680
Title:
Imaging and spectroscopy around PKS 0405-123
Short Name:
J/ApJ/643/680
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a galaxy survey of the field surrounding PKS 0405-123 performed with the WFCCD spectrometer at Las Campanas Observatory. The survey is comprised of two data sets: (1) a greater than 95% complete survey to R=20mag of the field centered on PKS 0405-123 with 10' radius (L~0.1L* and radius of 1Mpc at z=0.1); and (2) a set of four discontiguous (i.e., non-overlapping), flanking fields covering ~1deg^2^ area with completeness ~90% to R=19.5mag. With these data sets, one can examine the local and large-scale galactic environment of the absorption systems identified toward PKS 0405-123. In this paper, we focus on the O VI systems analyzed in Paper I (Prochaska et al., 2004, Cat. <J/ApJ/617/718>). The results suggest that this gas arises in a diverse set of galactic environments including the halos of individual galaxies, galaxy groups, filamentary-like structures, and also regions devoid of luminous galaxies. In this small sample, there are no obvious trends between galactic environment and the physical properties of the gas. Furthermore, we find similar results for a set of absorption systems with comparable NHI but no detectable metal lines. The observations indicate that metals are distributed throughout a wide range of environments in the local universe. Future papers in this series will address the distribution of galactic environments associated with metal-line systems and the Ly forest based on data for over 10 additional fields. All of the spectra and fits tables are available at http://www.ucolick.org/~xavier/WFCCDOVI/
2888. Imaging and spectroscopy in Lynx W
ID:
ivo://CDS.VizieR/J/AJ/148/117
Title:
Imaging and spectroscopy in Lynx W
Short Name:
J/AJ/148/117
Date:
21 Oct 2021
Publisher:
CDS
Description:
RX J0848.6+4453 (Lynx W) at redshift 1.27 is part of the Lynx Supercluster of galaxies. We present an analysis of the stellar populations and star formation history for a sample of 24 members of the cluster. Our study is based on deep optical spectroscopy obtained with Gemini North combined with imaging data from Hubble Space Telescope. Focusing on the 13 bulge-dominated galaxies for which we can determine central velocity dispersions, we find that these show a smaller evolution with redshift of sizes and velocity dispersions than reported for field galaxies and galaxies in poorer clusters. Our data show that the galaxies in RX J0848.6+4453 populate the fundamental plane (FP) similar to that found for lower-redshift clusters. The zero-point offset for the FP is smaller than expected if the cluster's galaxies are to evolve passively through the location of the FP we established in our previous work for z=0.8-0.9 cluster galaxies and then to the present-day FP. The FP zero point for RXJ0848.6+4453 corresponds to an epoch of last star formation at z_form_=1.95_-0.15_^+0.22^. Further, we find that the spectra of the galaxies in RXJ0848.6+4453 are dominated by young stellar populations at all galaxy masses and in many cases show emission indicating low-level ongoing star formation. The average age of the young stellar populations as estimated from the strength of the high-order Balmer line H{zeta} is consistent with a major star formation episode 1-2Gyr prior, which in turn agrees with z_form_=1.95. These galaxies dominated by young stellar populations are distributed throughout the cluster. We speculate that low-level star formation has not yet been fully quenched in the center of this cluster, possibly because the cluster is significantly poorer than other clusters previously studied at similar redshifts, which appear to have very little ongoing star formation in their centers. The mixture in RXJ0848.6+4453 of passive galaxies with young stellar populations and massive galaxies still experiencing some star formation appears similar to the galaxy populations recently identified in two z{approx}2 clusters.
2889. Imaging and spectroscopy in three galaxy clusters
ID:
ivo://CDS.VizieR/J/AJ/145/77
Title:
Imaging and spectroscopy in three galaxy clusters
Short Name:
J/AJ/145/77
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of stellar populations and evolutionary history of galaxies in three similarly rich galaxy clusters MS0451.6-0305 (z=0.54), RXJ0152.7-1357 (z=0.83), and RXJ1226.9+3332 (z=0.89). Our analysis is based on high signal-to-noise ground-based optical spectroscopy and Hubble Space Telescope imaging for a total of 17-34 members in each cluster. Using the dynamical masses together with the effective radii and the velocity dispersions, we find no indication of evolution of sizes or velocity dispersions with redshift at a given galaxy mass. We establish the Fundamental Plane (FP) and scaling relations between absorption line indices and velocity dispersions. We confirm that the FP is steeper at z~0.86 compared to the low-redshift FP, indicating that under the assumption of passive evolution the formation redshift, z_form_, depends on the galaxy velocity dispersion (or alternatively mass). At a velocity dispersion of {sigma}=125km/s (Mass=10^10.55^M_{sun}_) we find z_form_=1.24+/-0.05, while at {sigma}=225km/s (Mass=10^11.36^M_{sun}_) the formation redshift is z_form_=1.95^+0.3^_-0.2_, for a Salpeter initial mass function. The three clusters follow similar scaling relations between absorption line indices and velocity dispersions as those found for low-redshift galaxies. The zero point offsets for the Balmer lines depend on cluster redshifts. However, the offsets indicate a slower evolution, and therefore higher formation redshift, than the zero point differences found from the FP, if interpreting the data using a passive evolution model. Specifically, the strength of the higher order Balmer lines H{delta} and H{gamma} implies z_form_>2.8. The scaling relations for the metal indices in general show small and in some cases insignificant zero point offsets, favoring high formation redshifts for a passive evolution model.
2890. Imaging GRB 980425 in millimetic and submm
ID:
ivo://CDS.VizieR/J/A+A/562/A70
Title:
Imaging GRB 980425 in millimetic and submm
Short Name:
J/A+A/562/A70
Date:
21 Oct 2021
Publisher:
CDS
Description:
Gamma-ray bursts (GRBs) have been proposed as a tool to study star formation in the Universe, so it is crucial to investigate whether their host galaxies and immediate environments are in any way special compared with other star-forming galaxies. Here we present spatially resolved maps of dust emission of the host galaxy of the closest known GRB 980425 at z=0.0085 using our new high-resolution observations from Herschel, APEX, ALMA and ATCA. We modeled the spectral energy distributions of the host and of the star-forming region displaying the Wolf-Rayet signatures in the spectrum (WR region), located 800pc away from the GRB position. The host is characterised by low dust content and high fraction of UV-visible star-formation, similar to other dwarf galaxies. Such galaxies are abundant in the local universe, so it is not surprising to find a GRB in one of them, assuming the correspondence between the GRB rate and star-formation. The WR region contributes substantially to the host emission at the far-infrared, millimeter and radio wavelengths and we propose this to be a consequence of its high gas density. If dense environments are also found close to the positions of other GRBs, then the ISM density should also be considered as an important factor influencing whether a given stellar population can produce a GRB, in a similar way as metallicity.