The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. PESSTO classifies transients from publicly available sources and wide-field surveys, and selects science targets for detailed spectroscopic and photometric follow-up. PESSTO runs for nine months of the year, January - April and August - December inclusive, and typically has allocations of 10 nights per month. We describe the data reduction strategy and data products that are publicly available through the ESO archive as the Spectroscopic Survey data release 1 (SSDR1). PESSTO uses the New Technology Telescope with the instruments EFOSC2 and SOFI to provide optical and NIR spectroscopy and imaging. We target supernovae and optical transients brighter than 20.5^m^ for classification. Science targets are selected for follow-up based on the PESSTO science goal of extending knowledge of the extremes of the supernova population. We use standard EFOSC2 set-ups providing spectra with resolutions of 13-18{AA} between 3345-9995{AA}. A subset of the brighter science targets are selected for SOFI spectroscopy with the blue and red grisms (0.935-2.53{mu}m and resolutions 23-33{AA}) and imaging with broadband JHK_s_ filters. This first data release (SSDR1) contains flux calibrated spectra from the first year (April 2012-2013). A total of 221 confirmed supernovae were classified, and we released calibrated optical spectra and classifications publicly within 24h of the data being taken (via WISeREP). The data in SSDR1 replace those released spectra. They have more reliable and quantifiable flux calibrations, correction for telluric absorption, and are made available in standard ESO Phase 3 formats. We estimate the absolute accuracy of the flux calibrations for EFOSC2 across the whole survey in SSDR1 to be typically ~15%, although a number of spectra will have less reliable absolute flux calibration because of weather and slit losses. Acquisition images for each spectrum are available which, in principle, can allow the user to refine the absolute flux calibration. The standard NIR reduction process does not produce high accuracy absolute spectrophotometry but synthetic photometry with accompanying JHK_s_ imaging can improve this. Whenever possible, reduced SOFI images are provided to allow this. Future data releases will focus on improving the automated flux calibration of the data products. The rapid turnaround between discovery and classification and access to reliable pipeline processed data products has allowed early science papers in the first few months of the survey.
The Phoenix Deep Survey is a multiwavelength galaxy survey based on deep 1.4GHz radio imaging. The primary goal of this survey is to investigate the properties of star formation in galaxies and to trace the evolution in those properties to a redshift z=1, covering a significant fraction of the age of the universe. By compiling a sample of star-forming galaxies based on selection at radio wavelengths we eliminate possible biases due to dust obscuration, a significant issue when selecting objects at optical and ultraviolet wavelengths. In this paper, we present the catalogs and results of deep optical (UBVRI) and near-infrared (Ks) imaging of the deepest region of the existing decimetric radio imaging. The observations and data processing are summarized and the construction of the optical source catalogs described, together with the details of the identification of candidate optical counterparts to the radio catalogs. Based on our UBVRIKs imaging, photometric redshift estimates for the optical counterparts to the radio detections are explored.
Photoelectric observations of Cepheids in UBV(RI)c
Short Name:
II/285
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog gathers the observation of 894 Cepheids made between 1986 to 2004. Observations are listed in alphabetical order of the constellations. The standard deviation for every magnitude and color is 0.01mag. This version supersedes the 1997 edition (Cat. <II/217>)
The table gives individual absolute K and IRAS 12 and 25 luminosities of 800 LPVs. They are obtained by applying the Luri-Mennessier (LM, see below) calibration method to a sample composed of stars which are either of type M (O-rich), C (C-rich) or S (C/O~1), including Mira (M), SR (of both type a and b) and L variables. Astrometric data is taken exclusively from the HIPPARCOS Catalogue. Radial velocities are taken from the HIPPARCOS Input Catalogue. K band photometric data are gathered from various sources. Infrared magnitudes are derived from the fluxes measured by the IRAS satellite: m(12)=3.63-2.5log(F(12)) and m(25)=2.07-2.5log(F(25)) The stellar population from which the sample is extracted is assumed to be composed of several distinct groups that can differ in kinematics, luminosity or spatial distribution. The LM method determines the number of significant discriminating groups and produces, for each group, unbiased estimates of the mean parameters of the galactic and luminosity model. In a second step the method uses a Bayesian rule to statistically assign each star to a group. Table gives these assignations denoted as G(G') i.e. to group G in K and G'in IRAS. Three groups are identified in the K band. They can be interpreted as the galactic disk (D), old disk (OD) and extended disk (ED) populations. Four groups are identified in the IRAS bands. They are similar to those identified in the K band except that the old disk group is divided into ``bright'' (ODb) and ``faint'' (ODf) subgroups. Let us add that D, ODb and ED correspond to thick circumstellar envelope stars, while ODf is mainly composed of stars with a thin (or even lacking) envelope.
We present a homogeneous sample of 1361 L and T dwarfs brighter than J=17.5 (of which 998 are new), from an effective area of 3070deg^2^, classified by the photo-type method to an accuracy of one spectral sub-type using izY JHKW1W2 photometry from SDSS+UKIDSS+WISE. Other than a small bias in the early L types, the sample is shown to be effectively complete to the magnitude limit, for all spectral types L0 to T8. The nature of the bias is an incompleteness estimated at 3% because peculiar blue L dwarfs of type L4 and earlier are classified late M. There is a corresponding overcompleteness because peculiar red (likely young) late M dwarfs are classified early L. Contamination of the sample is confirmed to be small: so far spectroscopy has been obtained for 19 sources in the catalogue and all are confirmed to be ultracool dwarfs. We provide coordinates and izY JHKW1W2 photometry of all sources. We identify an apparent discontinuity, {Delta}m~0.4mag., in the Y-K colour between spectral types L7 and L8. We present near-infrared spectra of nine sources identified by photo-type as peculiar, including a new low-gravity source ULAS J005505.68+013436.0, with spectroscopic classification L2{gamma}. We provide revised izYJHKW1W2 template colours for late M dwarfs, types M7 to M9.
We present an analysis of deep multiwavelength data for z~0.3-3 starburst galaxies selected by their 70um emission in the Extended-Chandra Deep Field-South and Extended Groth Strip. We identify active galactic nuclei (AGNs) in these infrared sources through their X-ray emission and quantify the fraction that host an AGN. Lastly, we investigate the ratio between the supermassive black hole accretion rate (inferred from the AGN X-ray luminosity) and the bulge growth rate of the host galaxy (approximated as the SFR) and find that, for sources with detected AGNs and star formation (and neglecting systems with low star formation rates to which our data are insensitive), this ratio in distant starbursts agrees well with that expected from the local scaling relation assuming the black holes and bulges grew at the same epoch. These results imply that black holes and bulges grow together during periods of vigorous star formation and AGN activity.
We present time series photometric and spectroscopic data for the transient SN 2009ip from the start of its outburst in 2012 September until 2013 November. These data were collected primarily with the new robotic capabilities of the Las Cumbres Observatory Global Telescope Network, a specialized facility for time domain astrophysics, and includes supporting high-resolution spectroscopy from the Southern Astrophysical Research Telescope, Kitt Peak National Observatory, and Gemini Observatory. Based on our nightly photometric monitoring, we interpret the strength and timing of fluctuations in the light curve as interactions between fast-moving ejecta and an inhomogeneous circumstellar material (CSM) produced by past eruptions of this massive luminous blue variable (LBV) star. Our time series of spectroscopy in 2012 reveals that, as the continuum and narrow H{alpha} flux from CSM interactions declines, the broad component of H{alpha} persists with supernova (SN)-like velocities that are not typically seen in LBVs or SN impostor events. At late times, we find that SN 2009ip continues to decline slowly, at <~0.01 mag/day, with small fluctuations in slope similar to Type IIn supernovae (SNe IIn) or SN impostors but no further LBV-like activity. The late-time spectrum features broad calcium lines similar to both late-time SNe and SN impostors. In general, we find that the photometric and spectroscopic evolution of SN 2009ip is more similar to SNe IIn than either continued eruptions of an LBV star or SN impostors but we cannot rule out a nonterminal explosion. In this context, we discuss the implications for episodic mass loss during the late stages of massive star evolution.
Colour-magnitude diagrams form a traditional way of presenting luminous objects in the Universe and compare them to each other. Here, we estimate the photometric distance of 44 transiting exoplanetary systems. Parallaxes for seven systems confirm our methodology. Combining those measurements with fluxes obtained while planets were occulted by their host stars, we compose colour-magnitude diagrams in the near and mid-infrared. When possible, planets are plotted alongside very low mass stars and field brown dwarfs, who often share similar sizes and equilibrium temperatures. They offer a natural, empirical, comparison sample. We also include directly imaged exoplanets and the expected loci of pure blackbodies. Irradiated planets do not match blackbodies; their emission spectra are not featureless. For a given luminosity, hot Jupiters' daysides show a larger variety in colour than brown dwarfs do and display an increasing diversity in colour with decreasing intrinsic luminosity. The presence of an extra absorbent within the 4.5{mu}m band would reconcile outlying hot Jupiters with ultra-cool dwarfs' atmospheres. Measuring the emission of gas giants cooler than 1000K would disentangle whether planets' atmospheres behave more similarly to brown dwarfs' atmospheres than to blackbodies, whether they are akin to the young directly imaged planets, or if irradiated gas giants form their own sequence.
Photometric metallicities of stars in SkyMapper DR2
Short Name:
J/ApJS/254/31
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Milky Way's metal-poor stars are nearby ancient objects that are used to study early chemical evolution and the assembly and structure of the Milky Way. Here we present reliable metallicities of ~280000 stars with -3.75<~[Fe/H]<~-0.75 down to g=17 derived using metallicity-sensitive photometry from the second data release of the SkyMapper Southern Survey. We use the dependency of the flux through the SkyMapper v filter on the strength of the CaII K absorption features, in tandem with SkyMapper u, g, i photometry, to derive photometric metallicities for these stars. We find that metallicities derived in this way compare well to metallicities derived in large-scale spectroscopic surveys, and we use such comparisons to calibrate and quantify systematics as a function of location, reddening, and color. We find good agreement with metallicities from the APOGEE, LAMOST, and GALAH surveys, based on a standard deviation of {sigma}~0.25dex of the residuals of our photometric metallicities with respect to metallicities from those surveys. We also compare our derived photometric metallicities to metallicities presented in a number of high-resolution spectroscopic studies to validate the low-metallicity end ([Fe/H]{<}-2.5) of our photometric metallicity determinations. In such comparisons, we find the metallicities of stars with photometric [Fe/H]{<}-2.5 in our catalog show no significant offset and a scatter of {sigma}~0.31dex level relative to those in high-resolution work when considering the cooler stars (g-i>0.65) in our sample. We also present an expanded catalog containing photometric metallicities of ~720000 stars as a data table for further exploration of the metal-poor Milky Way.
