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We present direct imaging data of 22 ultra steep spectrum radio sources obtained at (or near) a subarcsecond seeing. The basic sample of 40 double radio sources was selected from the RATAN-600 catalogue. The FRII-structure has been confirmed with VLA and preliminary optical identifications which come from the 6 m-telescope. As the RATAN-600 flux li...
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We measure the molecular-to-atomic gas ratio, R mol , and the star formation rate (SFR) per unit molecular gas mass, SFE mol , in 38 nearby galaxies selected from the Virgo Environment Traced in CO (VERTICO) survey. We stack ALMA ¹² CO ( J = 2−1) spectra coherently using H i velocities from the VIVA survey to detect faint CO emission out to galacto...
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Citations
... In 1991-2003, about 80 observational nights were allocated for the optical identification of the SS sample on the 6-m BTA telescope. Direct images of subsecond (or close to it) seeing for 22 radio sources were also obtained with the 2-m Nordic Telescope [3]. For most of the sources (94%) of the sample, optical counterparts were found. ...
We consider a sample of 412 galaxies with radial velocities $V_{\rm LG} < 2500$ km s$^{-1}$ situated in the sky region of ${\rm RA}=13^h\hspace{-0.4em}.\,0$ ... $19^h\hspace{-0.4em}.\,0$, ${\rm Dec}=+10^{\circ}$ ... $+40^{\circ}$ between the Local Void and the Supergalactic plane. One hundred and eighty-one of them have individual distance estimates. Peculiar velocities of the galaxies as a function of Supergalactic latitude SGB show signs of Virgocentric infall at $SGB < 10^{\circ}$ and motion from the Local Void at $SGB > 60^{\circ}$. A half of the Hercules-Bootes galaxies belong to 17 groups and 29 pairs, with the richest group around NGC5353. A typical group is characterized by the velocity dispersion of $67$ km s$^{-1}$, the harmonic radius of $182$ kpc, the stellar mass of $4.3 \times10^{10} M_{\odot}$ and the virial-to-stellar mass ratio of $32$. The binary galaxies have the mean radial velocity difference of $37$ km s$^{-1}$, the projected separation of $96$ kpc, the mean integral stellar mass of $2.6\times 10^9 M_{\odot}$ and the mean virial-to-stellar mass ratio of about $8$. The total dark-matter-to-stellar mass ratio in the considered sky region amounts to $37$ being almost the same as that in the Local Volume.
Fields of the Planck cosmic-microwave background maps in the regions of radio sources of the RCR catalog have been studied. Using measurements from the Planck catalog, calibration curves have been plotted in order to determine the objects’ luminosities. The flux densities at millimeter and submillimeter wavelengths of 83 objects with normal radio spectra have been estimated for the first time; their spectra have also been constructed, they have been optically identified, and information available in various databases has been collected. A statistical comparison with a sample of sources with steep radio spectra has been carried out. Faint, difficult to characterize microwave sources make an additional contribution to the secondary anisotropy on angular scales < 7′. An algorithm for selecting candidate objects with the Sunyaev–Zel’dovich effect has been proposed, based on the use of data on the radio spectral indices and the signal in cosmic-microwave background maps.
We have investigated the regions of cosmic microwave background maps from the Planck experiment in the neighborhoods of radio sources from the RCR catalog. Based on the measurements of sources from the Planck catalog, we have constructed the calibration curves to determine the brightness of objects. For 34 steep-spectrum objects, for the first time we have estimated the flux densities at millimeter and submillimeter wavelengths, constructed the spectra, made identifications, and gathered information available in databases. Faint, difficult-to-clean, microwave sources make an additional contribution to the secondary anisotropy on angular scales <7′.
We have studied the regions of the microwave background radiation maps of the Planck experiment in the neighborhood of the RCR catalog radio sources. From the processed data for bright radio sources in the microwave range, we plotted the calibration curves which allow the brightness of the objects to be measured. For the first time, for 117 objects we obtained estimates of flux density at the millimeter and submillimeter waves, prepared the spectra, conducted identification, and gathered available information from databases. Faint microwave sources, difficult to clear out, additionally contribute to the secondary anisotropy at angular scales smaller than 7′.
Radio sources of the RCR catalogue, obtained from observational data of the “Cold” experiment, have been identified, almost completely, with optical objects. For this purpose, we used optical, infrared, and radio sky surveys as well as archive data from the VLA (NRAO) and the 6-m telescope (SAO). According to spectroscopy and color index constraints, the identified sources are classified as galaxies and quasars; about 20 % of the sources remain unclassified because of being optically faint. We estimated radio luminosities of the sources and found that a majority (60%) of them belong to strong radio sources. Using ratios of FIRST and NVSS flux densities and angular sizes, we prepared a sample of steep spectrum compact sources. The existing infrastructure of the virtual observatory increases the effectiveness of astronomical studies like ours greatly. However, we still cannot consider the virtual observatory a completed project because it requires further development of services providing actualization of user data and better semantic compatibility of information. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
We present early results of our multiband study of the RATAN Cold
Revised (RCR) catalogue obtained from seven cycles of the ``Cold''
survey carried with the RATAN-600 radio telescope at 7.6 cm in
1980--1999, at the declination of the SS 433 source. We used the 2MASS
and LAS UKIDSS infrared surveys, the DSS-II and SDSS DR7 optical
surveys, as well as the USNO-B1 and GSC-II catalogues, the VLSS, TXS,
NVSS, FIRST and GB6 radio surveys to accumulate information about the
sources. For radio sources that have no detectable optical candidate in
optical or infrared catalogues, we additionally looked through images in
several bands from the SDSS, LAS UKIDSS, DPOSS, 2MASS surveys and also
used co-added frames in different bands. We reliably identified 76% of
radio sources of the RCR catalogue. We used the ALADIN and SAOImage DS9
scripting capabilities, interoperability services of ALADIN and TOPCAT,
and also other Virtual Observatory (VO) tools and resources, such as
CASJobs, NED, Vizier, and WSA, for effective data access, visualization
and analysis. Without VO tools it would have been problematic to perform
our study.
FIRST and NVSS radio maps are used to cross identify the radio sources of the RCR catalog, which is based on observational data obtained in several runs of the “Cold” survey, with the SDSS and DPOSS digital optical sky surveys and the 2MASS, LAS UKIDSS, and WISE infrared surveys. Digital images in various filters and the coadded gri-band SDSS images, red and infrared DPOSS images, JHK-band UKIDSS images, and JHK-band 2MASS images are analyzed for the sources with no optical candidates found in the above catalogs. Our choice of optical candidates was based on the data on the structure of the radio source, its photometry, and spectroscopy (where available). We found reliable identifications for 86% of the radio sources; possible counterparts for 8% of the sources, and failed to find any optical counterparts for 6% of the sources because their host objects proved to be fainter than the limiting magnitude of the corresponding surveys. A little over half of all the identifications proved to be galaxies; about one quarter were quasars, and the types of the remaining objects were difficult to determine because of their faintness. A relation between the luminosity and the radioloudness index was derived and used to estimate the 1.4 and 3.94 GHz luminosities for the sources with unknown redshifts. We found 3% and 60% of all the RCR radio sources to be FRI-type objects (L ≲ 1024 W/Hz at 1.4 GHz) and powerful FRII-type galaxies (L ≳ 1026.5 W/Hz), respectively, whereas the rest are sources including objects of the FRI, FRII, and mixed FRI-FRII types. Unlike quasars, galaxies show a trend of decreasing luminosity with decreasing flux density. Note that identification would be quite problematic without the software and resources of the virtual observatory.
Powerful radio galaxies belong to the population of massive stellar systems that can be picked at high redshifts. With measured redshift, morphology and age determination these objects can help greatly in understanding of the way of formation and evolution of giant elliptical galaxies with massive Black Holes in the Early Universe. We presents some recent results of study of the sample of 105 faint steep spectrum radio sources from RATAN-600 RC catalogue. All the objects has been mapped with the VLA and optical identification have been carried out with the 6m BTA telescope. Using multicolour CCD photometry in B,V,R_c,I_c bands photometric redshift and age of stellar population are estimated for a subsample of 50 FRII and CSS radio galaxies. RC J0105+0501 is a very probable candidate for radio galaxy at z ~ 3.5. Distribution of objects on colour-colour and magnitude-redshift diagrams shows a rough agreement with expectations of theoretical models of SED evolution for giant elliptical galaxies. On the [m_R - z_{phot}] diagram two populations of faint (m_R = 22^m-24^m) radio galaxies are possibly revealed. The first population at z~ 1 consists of mainly old (a half with age >= 5 Gyr) and large (LAS~20") objects, the second one at z = 1.5 - 3.5 includes both younger (<= 3 Gyr) and smaller (LAS ~ 5") objects. There are 12 more faint or still undetected (m_R >= 24.5^m) sources in the sample which may presumably be a very distant radio galaxies (z>3.5) or intermediate redshift old or dusty ones. Comment: 8 pages, 3 figures, uses psfig.sty. This was the poster as presented on Gamow Memorial Intern. Conf. GMIC'99 "Early Universe: Cosmological Problems and Instrumental Technologies" in St.Petersburg, 23-27 Aug., 1999. Submitted to Proceedings, to be published in A&A Transactions. Partly presented as a Poster on IAU Symp.199, Puna, India
The results of spectroscopic observations of the host galaxies of objects in the RC catalog (the “Big Trio” program) obtained
using the new SCORPIO spectrograph of the Special Astrophysical Observatory are presented. The spectroscopic redshifts of
the objects are compared with their photometric color redshifts, and the errors in the latter are estimated. Based on BV RI observations obtained on the 6-m telescope of the SAO, the errors for the population of powerful radio galaxies are close
to those found previously for radio quiet galaxies (about 10–20%). The detection of Ly α in the B filter in RC 1626+0448 is confirmed. This object is the second spectrally studied FR II radio source from the RC catalog
to have a redshift z>2.5. Star formation in its host galaxy began at a redshift z>3.3. This first use of the new SCORPIO spectrograph demonstrates its promise for studies of very distant steep-spectrum radio
galaxies brighter than 23m–24m in V.
