- ID:
- ivo://CDS.VizieR/J/A+AS/115/235
- Title:
- The Hamburg/ESO survey for bright QSOs. II.
- Short Name:
- J/A+AS/115/235
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report about the first phase of a wide-angle survey for bright QSOs (12.5<~B<~17.5) in the southern hemisphere, based on objective prism plates taken with the ESO Schmidt telescope over an effective area of ~1000 sq.deg. After digitisation, the extracted spectra were searched for quasar candidates in a largely automated two-stage procedure. Several selection criteria, such as UV excess or presence of emission lines, were applied simultaneously to the databases. Thanks to the high spectral resolution of the spectra, the stellar contamination in the candidate sets could be efficiently kept low. Follow-up spectroscopy has yielded 160 newly discovered QSOs and Seyfert 1 galaxies, plus a variety of other interesting galactic and extragalactic objects. Although the present QSO sample is not statistically "complete" insofar as it has no well-defined flux limit, there is no evidence for strong redshift-dependent selection biases. The extension of the survey over an area of 5000sq.deg. and the construction of flux-limited subsamples are under way.
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- ID:
- ivo://CDS.VizieR/J/A+AS/128/507
- Title:
- The Hamburg Quasar Survey. II.
- Short Name:
- J/A+AS/128/507
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hamburg Quasar Survey is a wide-angle objective prism survey for finding bright QSOs in the northern extragalactic sky (|b|>20{deg}; {delta}>0{deg}). The taking of the prism plates for 567 fields covering this area was completed in 1997. Including direct plates for fields with {delta}> 20{deg} the plate archive contains now 1871 plates. In this paper we present a first list of 121 quasars, which were verified by slit spectroscopy in the years 1986-1991, while experiments to develop efficient selection techniques were made. The sample contains objects with brightnesses 15<=B<=19.5 and redshifts z<=2.8 collected over various parts of the sky, for which objective prism plates were available at that time.
- ID:
- ivo://CDS.VizieR/J/A+AS/134/483
- Title:
- The Hamburg Quasar Survey. III.
- Short Name:
- J/A+AS/134/483
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 3 lists for all new QSOs the position for equinox 2000.0 with an accuracy ~2", the B magnitude obtained from the Schmidt plates with an accuracy ~<0.5 (see Paper I, Hagen et al., 1995A&AS..111..195H), the redshift, and the number of the campaign of Table 2 in which the data were obtained.
- ID:
- ivo://CDS.VizieR/J/A+AS/135/511
- Title:
- The Hamburg/SAO Survey for ELGs
- Short Name:
- J/A+AS/135/511
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present first results of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAO - Special Astrophysical Observatory, Russia) which is based on the digitized objective-prism photoplates database of the Hamburg Quasar Survey (HQS). The main goal of this survey is the search for emission-line galaxies (ELG) in order to create a new deep sample of blue compact galaxies (BCG) in a large sky area. Another important goal of this work is to search for new extremely low-metallicity galaxies. We present the first results of spectroscopy obtained with the 2.2m telescope at the German-Spanish Observatory at Calar Alto, and with the 6m telescope at the Russian Special Astrophysical Observatory. The primary ELG candidate selection criteria applied were a blue continuum (near 4000{AA}) and the presence of emission lines close to 5000A recognized on digitized prism spectra of galaxies with magnitudes in the range B =16.0-19.5. The spectroscopy resulted in the detection or/and quantitative spectral classification of 74 emission-line objects. Of them 55 are newly discovered, and 19 were already known as galaxies before. 11 of the latter have redshifts and are known ELGs. For most of the known galaxies emission line ratios were measured for the first time and an improved classification is presented. 47 objects are classified as BCGs, one as Sy2 galaxy, six as probable LINERs, and four as new QSOs. The remaining galaxies do not show significant H{beta} and [OIII]4959,5007{AA} emission lines, and are likely either low-ionization starburst or dwarf amorphous nuclear starburst galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/2840
- Title:
- The 2M++ galaxy redshift catalogue
- Short Name:
- J/MNRAS/416/2840
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Peculiar velocities arise from gravitational instability, and thus are linked to the surrounding distribution of matter. In order to understand the motion of the Local Group with respect to the cosmic microwave background, a deep all-sky map of the galaxy distribution is required. Here we present a new redshift compilation of 69160 galaxies, dubbed 2M++, to map large-scale structures of the local Universe over nearly the whole sky, and reaching depths of K<=12.5, or 200h^-1^Mpc. The target catalogue is based on the Two-Micron All-Sky Survey Extended Source Catalog (2MASS-XSC). The primary sources of redshifts are the 2MASS Redshift Survey, the 6dF galaxy redshift survey and the Sloan Digital Sky Survey (Data Release 7). We assess redshift completeness in each region and compute the weights required to correct for redshift incompleteness and apparent magnitude limits, and discuss corrections for incompleteness in the zone of avoidance. We present the density field for this survey, and discuss the importance of large-scale structures such as the Shapley Concentration.
- ID:
- ivo://CDS.VizieR/VII/277
- Title:
- The Million Quasars (Milliquas) catalog
- Short Name:
- VII/277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is a compendium of 452,794 type-I QSOs and AGN, largely complete from the literature to 21 June 2016. Also included are ~900K high-confidence quasar candidates from SDSS-based photometric quasar catalogs (of 90%+ likelihood) and from all-sky radio/X-ray associated objects (of 80%+ likelihood). Type-II and Bl Lac objects are also included, bringing the total count to 1,422,219. This version is the same as v4.8 but with these changes: (1) The 3XMM-DR6 X-ray source catalog (www.cosmos.esa.int/web/xmm-newton/xsa) has been added and new X-ray associations calculated. (2) Radio/X-ray data have been reprocessed in line with that of the new Million Optical Radio/X-ray (MORX) associations catalogue, in preparation. The catalog format is simple, each object is shown as one line bearing the J2000 coordinates, its original name, object class, red and blue optical magnitudes, PSF class, redshift, the citations for the name and redshift, plus up to four radio/X-ray identifiers where applicable. Questions/comments/praise/complaints may be directed to Eric Flesch at eric(at)flesch.org.
- ID:
- ivo://CDS.VizieR/VII/280
- Title:
- The Million Quasars (Milliquas) catalog (V5.2)
- Short Name:
- VII/280
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is a compendium of 607,208 type-I QSOs and AGN, largely complete from the literature to 5-August-2017, including the release of SDSS-DR14. Also included are ~1.35M high-confidence (80%+ likelihood) quasar candidates from the NBCKDE, NBCKDE-v3, XDQSO, AllWISE and Peters photometric quasar catalogs (citations in Note 7 below) and from all-sky radio/X-ray associated objects which are calculated here. Type-II and Bl Lac objects are also included, bringing the total count to 1,998,464. Changes from version 5.1 are: (1) SDSS-DR14 and SDSS-DR14Q have been added, using the processing rules from the Half Million Quasars catalog (HMQ: Flesch 2015PASA...32...10F). (2) WISE quasar candidates have been added from Secrest et al, 2015, Cat. J/ApJS/221/12; these are ~430K candidates over the whole sky for which 2-color optical objects were found within a 2-arcsec radius. They have been processed into pQSOs from calibration against the SDSS-DR12Q multi-class superset, and photometric redshifts obtained using the four-color based method from the HMQ appendix 2. The four colors used were B-R, R-W1, W1-W2 & W2-W3. (3) Type-II narrow emission-line galaxies, (NELGs, class='N') are added as the luminosity class corresponding to the type-I AGN galaxies. High-luminosity type-II NLAGN (class='K') correspond to the type-I quasars. The NLAGN/NELG divider is the same luminosity/psf function which separates QSOs from AGNs. Type-II NELGs include unquantified contamination by LINERs and probably a few starbursts which eluded removal, so it serves as a catch-all category presented for completeness, rather than as a strict type-II class. (4) Small publications to 5 August 2017 have been added. (5) Positional fixes (of about 2 arcsec) have been applied to ~150 objects. Low-confidence or questionable objects (so deemed by their researchers) are not included in Milliquas. Additional quality cuts can be applied as detailed in Flesch 2015PASA...32...10F). Multiple lensed images are excluded and only the brightest one kept. The aim here is to present one unique reliable object per each data row. The catalog format is simple, each object is shown as one line bearing the J2000 coordinates, its original name, object class, red and blue optical magnitudes, PSF class, redshift, the citations for the name and redshift, plus up to four radio/X-ray identifiers where applicable. This catalog can be cited as Milliquas, Flesch E., 2015PASA...32...10F which was the published version of this catalog as at 2015 after the release of SDSS-DR12. Questions/comments/praise/complaints may be directed to me at eric(at)flesch.org.
378. The Phoenix Survey
- ID:
- ivo://CDS.VizieR/J/MNRAS/306/708
- Title:
- The Phoenix Survey
- Short Name:
- J/MNRAS/306/708
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a deep Australia Telescope Compact Array (ATCA) radio survey covering an area of ~3deg^2^ to a 4{sigma} sensitivity of >=100mmJy at 1.4GHz, we study the nature of faint radio galaxies. About 50 per cent of the detected radio sources are identified with an optical counterpart revealed by CCD photometry to m_R=22.5mag. Near-infrared (K-band) data are also available for a selected sample of the radio sources, while spectroscopic observations have been carried out for about 40 per cent of the optically identified sample. These provide redshifts and information on the stellar content. Emission-line ratios imply that most of the emission-line sources are star-forming galaxies, with a small contribution (~10 per cent) from Sy1/Sy2 type objects. We also find a significant number of absorption-line systems, likely to be ellipticals. These dominate at high flux densities (>1mJy) but are also found at sub-mJy levels. Using the Balmer decrement we find a visual extinction A_V_=1.0 for the star-forming faint radio sources. This moderate reddening is consistent with the V-R and R-K colours of the optically identified sources. For emission-line galaxies, there is a correlation between the radio power and the Halpha luminosity, in agreement with the result of Benn et al. (1993MNRAS.263....9B). This suggests that the radio emission of starburst radio galaxies is a good indicator of star formation activity.
- ID:
- ivo://CDS.VizieR/J/A+AS/116/203
- Title:
- The redshift catalogue for galaxy clusters
- Short Name:
- J/A+AS/116/203
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An extensive redshift survey has been conducted on a sample of 15 nearby (0.01<~z<~0.05) clusters of galaxies. A total number of 860 redshifts were determined by fitting of emission-lines and/or cross-correlation techniques. Of this sample, 735 galaxies are within 0.2-0.8Mpc (H_0_=50km/s/Mpc) of the center of clusters. Approximate morphological types are available for most of the galaxies. A comparison of the present redshifts with published data allows an extensive error analysis. The agreement is excellent with the most modern data, showing a zero point error of 5km/s and an overall consistency of the measurements and their uncertainties. We estimate our redshifts to have mean random errors around 30km/s. A population analysis of the clusters will be given in a forthcoming paper.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/3895
- Title:
- The rising light curves of Type Ia supernovae
- Short Name:
- J/MNRAS/446/3895
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the early, rising light curves of 18 Type Ia supernovae (SNe Ia) discovered by the Palomar Transient Factory and the La Silla-QUEST variability survey. We fit these early data flux using a simple power law (f(t)={alpha}xt^n^) to determine the time of first light (t_0_), and hence the rise time (t_rise_) from first light to peak luminosity, and the exponent of the power-law rise (n). We find a mean uncorrected rise time of 18.98+/-0.54 d, with individual supernova (SN) rise times ranging from 15.98 to 24.7 d. The exponent n shows significant departures from the simple `fireball model' of n=2 (or f(t){prop.to}t^2^) usually assumed in the literature. With a mean value of n=2.44+/-0.13, our data also show significant diversity from event to event. This deviation has implications for the distribution of ^56^Ni throughout the SN ejecta, with a higher index suggesting a lesser degree of ^56^Ni mixing. The range of n found also confirms that the ^56^Ni distribution is not standard throughout the population of SNe Ia, in agreement with earlier work measuring such abundances through spectral modelling. We also show that the duration of the very early light curve, before the luminosity has reached half of its maximal value, does not correlate with the light-curve shape or stretch used to standardize SNe Ia in cosmological applications. This has implications for the cosmological fitting of SN Ia light curves.
