We present star formation activity in the infrared dark cloud (IRDC) G53.2, a remarkable IRDC located at Galactic coordinates (l,b)~(53.2{deg},0.0{deg}) based on the census of young stellar object (YSO) candidates. IRDC G53.2 was previously identified as several IRDCs in mid-IR images, but it is in fact a long (>~45pc) cloud, well consistent with a CO cloud at v~23km/s (or at d~1.7kpc). We present a point-source catalog of IRDC G53.2 that contains ~370 sources from our photometry of the Spitzer MIPS 24{mu}m data and Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) Catalog. The classification of the identified sources based on their spectral index and control field analysis to remove field star contamination reveals that IRDC G53.2 is an active star-forming region with ~300 YSO candidates. We compare the YSO classification based on spectral index, mid-IR colors, and the wavelength range used, which results in consistent classification, except for flat-spectrum objects, with some ambiguity between Class I and II. Comparison of the YSO population in IRDC G53.2 with those of other nearby star-forming clusters indicates that they are similar in age; on the other hand, stronger association with mid-IR stellar sources in IRDC G53.2 compared with other IRDCs indicates that IRDC G53.2 is at a later evolutionary stage among IRDCs. Spatial distribution of the YSO candidates in IRDC G53.2 shows a good correlation with ^13^CO column density and far-IR emission, and earlier-class objects tend to be more clustered in the regions with higher density.
This is a course on the Virtual Observatory's main query language
ADQL (short for Astronomical Data Query Language), which is a SQL
dialect standardised so users do not have to learn new languages each
time they want to use a new resource. We also introduce the basic
aspects of the Table Access Protocol TAP, which transports ADQL
queries, their results as well as the metadata necessary to write
meaningful queries.
The course comes with many exercises, most of which also have
solutions. We hope it is suitable for both self-study and as lecture
notes in teacher-led situations.
This is a course on pyVO, an astropy-affiliated Python library
implementing client parts for many protocols in the Virtual
Observatory: Simple discovery protocols like SCS, SIAP, and SSAP as
well as the sophisticated Table Access Protocol TAP, which allows
users to send complex queries to remote tables and retrieve
metadata-rich results. There is also an interface to the VO Registry
to enable data and service discovery.
The course comes with many exercises, most of which also have
solutions. We hope it is suitable for both self-study and as lecture
notes in teacher-led situations.
The Asiago Catalog of 2004 Quasi Stellar Objects (QSOs) is an updated version of that published by Barbieri, Capaccioli and Zambon in 1975 (1975MmSAI..46..461B). Most of the information of these objects are taken from the literature published before Dec. 31, 1981. Specifically, the catalog.dat file contains names, equatorial and galactic coordinates, photometry, redshifts, information on radio emission, variability, morphology, presence of absorption lines, for 2004 QSOs. The indexed references (in refs.dat) and further detailed information (in remarks.dat) concerning absorption spectra, X-ray properties, and cross-reference tables are also provided.
This paper presents the first results of a survey for bright quasars (V<14.5 and R<15.4) covering the northern hemisphere at Galactic latitudes |b|>30{deg}. The photometric database is derived from the Guide Star and USNO catalogs. Quasars are identified on the basis of their X-ray emission measured in the ROSAT All-Sky Survey. The surface density of quasars brighter than 15.5mag turns out to be (10+/-2)x10^-3^deg^-2^, about 3 times higher than that estimated by the Palomar-Green (PG) survey. The quasar optical luminosity function (LF) at 0.04<z<=0.3 is computed and shown to be consistent with a luminosity-dependent luminosity evolution of the type derived by La Franca & Cristiani (1997AJ....113.1517L) in the range 0.3<z<=2.2. The predictions of semianalytical models of hierarchical structure formation agree remarkably well with the present observations.
This is the second paper of a series describing the Asiago-ESO/RASS QSO survey, a project aimed at the construction of an all-sky, statistically well defined sample of very bright QSOs (BJ<=15). Such a survey is required to remove the present uncertainties about the properties of the local QSO population and constitutes an homogeneous database for detailed evolutionary studies of active galactic nuclei (AGNs). We present here the complete southern sample, which comprises 243 bright (12.60<=BJ<=15.13) QSO candidates at high galactic latitudes (|b_gal_|>=30{deg}). The area covered by the survey is 5660deg^2^. Spectroscopy for the 137 still unidentified objects has been obtained. The total number of AGNs turns out to be 11163 of which are new identifications. The properties of the selection are discussed. The completeness and the success rate for this survey at the final stage are 63% and 46%, respectively.
This table contains the dynamic version of the Asiago Supernova Catalog. It supersedes the original 1999 version by Barbon et al. (1999A&AS..139..531B, Cat. II/227), and contains data about the supernovae observed since 1885 and their parent galaxies through a few days prior to the most recent update. In addition to the list of newly discovered SNe, the literature has been searched for new information on past SNe as well. The data for the parent galaxies have also been homogenized. This table was created by the HEASARC based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/sn">CDS Catalog B/sn</a>. The CDS updates it regularly, and this HEASARC version is accordingly updated within a week of such updates. This is a service provided by NASA HEASARC .
This catalogue supersedes the previous version by Barbon et al. (1999A&AS..139..531B, Cat. II/227), and contains data about the supernovae observed since 1895 and their parent galaxies, and is regularly updated. In addition to the list of newly discovered SNe, the literature has been searched for new information on past SNe as well. The data for the parent galaxies have also been homogenized.
This catalogue (Table 1 of the Publication) tabulates the main data relative to all extragalactic supernovae discovered up to 1988 December 31, and to their parent galaxies. In total 661 SNe are listed of which 267 are classified.
This catalogue supersedes the previous version by Barbon et al. (1999A&AS..139..531B, Cat. II/227), and contains data about the supernovae observed since 1895 and their parent galaxies until the beginning of 2008. In addition to the list of newly discovered SNe, the literature has been searched for new information on past SNe as well. The data for the parent galaxies have also been homogenized.
