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3431. CRTS close supermassive black hole binaries
ID:
ivo://CDS.VizieR/J/MNRAS/453/1562
Title:
CRTS close supermassive black hole binaries
Short Name:
J/MNRAS/453/1562
Date:
21 Oct 2021
Publisher:
CDS
Description:
Hierarchical assembly models predict a population of supermassive black hole (SMBH) binaries. These are not resolvable by direct imaging but may be detectable via periodic variability (or nanohertz frequency gravitational waves). Following our detection of a 5.2-year periodic signal in the quasar PG 1302-102, we present a novel analysis of the optical variability of 243 500 known spectroscopically confirmed quasars using data from the Catalina Real-time Transient Survey (CRTS) to look for close (<0.1pc) SMBH systems. Looking for a strong Keplerian periodic signal with at least 1.5 cycles over a baseline of nine years, we find a sample of 111 candidate objects. This is in conservative agreement with theoretical predictions from models of binary SMBH populations. Simulated data sets, assuming stochastic variability, also produce no equivalent candidates implying a low likelihood of spurious detections. The periodicity seen is likely attributable to either jet precession, warped accretion discs or periodic accretion associated with a close SMBH binary system. We also consider how other SMBH binary candidates in the literature appear in CRTS data and show that none of these are equivalent to the identified objects. Finally, the distribution of objects found is consistent with that expected from a gravitational-wave-driven population. This implies that circumbinary gas is present at small orbital radii and is being perturbed by the black holes. None of the sources is expected to merge within at least the next century. This study opens a new unique window to study a population of close SMBH binaries that must exist according to our current understanding of galaxy and SMBH evolution.
3432. Crux region redshifts
ID:
ivo://CDS.VizieR/J/A+AS/127/463
Title:
Crux region redshifts
Short Name:
J/A+AS/127/463
Date:
21 Oct 2021
Publisher:
CDS
Description:
In our systematic optical galaxy search behind the southern Milky Way, 3760 (mostly unknown) galaxies with diameters D>0.2' were identified in the Crux region (287{deg}<~l<~318{deg}, |b|<~10{deg}, Woudt & Kraan-Korteweg 1998, in press). Prior to this investigation, only 65 of these galaxies had known redshifts. In order to map the galaxy distribution in redshift space we obtained spectra for 226 bright (B_J_<~18.0mag) objects with the 1.9m telescope of the South African Astronomical Observatory (SAAO). Redshifts could be determined for 209 objects, of which 173 have good signal-to-noise ratios. Of the 36 tentative redshifts, four are confirmed through independent values in the literature. The redshifts of three objects indicate them to be galactic in origin. One of these confirms a suspected Planetary Nebula. For 17 of the galaxies, no redshift could be determined due to poor signal-to-noise ratios. In addition, 26 redshifts have have been measured in the Hydra-Antlia region investigated earlier (Kraan-Korteweg et al., 1995, Cat. <J/A+A/297/617>), of which one is a tentative estimate. Two main structures crossing the Galactic Plane in the Crux region have now become clear. A narrow, nearby filament from (l, b)=(340{deg}, -25{deg}) to the Centaurus cluster can be traced. This filament runs almost parallel to the extension of the Hydra-Antlia clusters found earlier and is part of what we have earlier termed the ``Centaurus Wall'' extending in redshift-space between 0<=v<=6000km/s (Fairall & Paverd 1995, in Wide-Field Spedctroscopy and the Distant Universe, p. 121). The main outcome of this survey however, is the recognition of another massive extended structure between 4000<=v<=8000km/s. This broad structure, dubbed the Norma Supercluster (Woudt et al. 1997, in press), runs nearly parallel to the Galactic Plane from Vela to ACO 3627 (its centre) from where it continues to the Pavo cluster. This massive structure is believed to be associated with the Great Attractor. The survey has furthermore revealed a set of cellular structures, similar to those seen in redshift space at higher galactic latitudes, but never before seen so clearly behind the Milky Way.
3433. Crystalline silicates around evolved stars
ID:
ivo://CDS.VizieR/J/A+A/382/184
Title:
Crystalline silicates around evolved stars
Short Name:
J/A+A/382/184
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the first paper in a series of three where we present the first comprehensive inventory of solid state emission bands observed in a sample of 17 oxygen-rich circumstellar dust shells surrounding evolved stars. The data were taken with the Short and Long Wavelength Spectrographs on board of the Infrared Space Observatory (ISO) and cover the 2.4 to 195{mu}m wavelength range. The spectra show the presence of broad 10 and 18{mu}m bands that can be attributed to amorphous silicates. In addition, at least 49 narrow bands are found whose position and width indicate they can be attributed to crystalline silicates. Almost all of these bands were not known before ISO.
3434. 6C** sample of steep-spectrum radio sources
ID:
ivo://CDS.VizieR/J/MNRAS/373/1531
Title:
6C** sample of steep-spectrum radio sources
Short Name:
J/MNRAS/373/1531
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present basic observational data on the 6C** sample. This is a new sample of radio sources drawn from the 151-MHz 6C survey, which was filtered with radio criteria chosen to optimize the chances of finding radio galaxies at z>4. The filtering criteria are a steep-spectral index and a small angular size. The final sample consists of 68 sources from a region of sky covering 0.421sr. We present Very Large Array radio maps, and the results of K-band imaging and optical spectroscopy.
3435. 6C** sample of steep-spectrum radio sources. II
ID:
ivo://CDS.VizieR/J/MNRAS/375/1349
Title:
6C** sample of steep-spectrum radio sources. II
Short Name:
J/MNRAS/375/1349
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use the 6C** sample to investigate the comoving space density of powerful, steep-spectrum radio sources. This sample, consisting of 68 objects, has virtually complete K-band photometry and spectroscopic redshifts for 32 per cent of the sources. In order to find its complete redshift distribution, we develop a method of redshift estimation based on the Kz diagram of the 3CRR, 6CE, 6C* and 7CRS radio galaxies. Based on this method, we derive redshift probability density functions for all the optically identified sources in the 6C** sample. Using a combination of spectroscopic and estimated redshifts, we select the most radio luminous sources in the sample. Their redshift distribution is then compared with the predictions of the radio luminosity function of Jarvis et al. (2001MNRAS.327..907J). We find that, within the uncertainties associated with the estimation method, the data are consistent with a constant comoving space density of steep-spectrum radio sources beyond z>2.5, and rule out a steep decline.
3436. CS and NH3 Survey of H2O Maser Emission
ID:
ivo://CDS.VizieR/J/ApJ/463/205
Title:
CS and NH3 Survey of H2O Maser Emission
Short Name:
J/ApJ/463/205
Date:
21 Oct 2021
Publisher:
CDS
Description:
CS J=1-0 and NH(J,K)=(1,1) observations toward a large sample of H2O maser regions are reported. A total of 172 sources were observed. 107 were observed in CS and 164 in NH_3_. The main purpose of this work was to study the relationship between the parameters that characterize the high velocity H2O maser emission, which originates in very small (about 10 AU) and very dense (10^7-10^9/cm^3^) regions, and those that characterize the molecular emission coming from quiescent, more extended (0.1-1.0 pc) high density (10^4-10^5/cm^3^) regions, traced by the CS and NH_3_ emissions. The observations were carried out between 1986 and 1990 with the 37 m radio telescope at Haystack Observatory The emission of the (J,K)=(1,1) inversion transition of the NH_3_ molecule at 23.694496 GHz, and the emission of the J=1->0 rotational transition of the CS molecule at 48.990968 GHz were observed.
3437. CSI2264 CoRoT Light Curve Table
ID:
ivo://irsa.ipac/Spitzer/Catalog/CSI2264/CSI2264_CoRoT_LC
Title:
CSI2264 CoRoT Light Curve Table
Short Name:
CSI2264 CoRoT LC
Date:
01 Oct 2018 20:27:17
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The CSI 2264 project performed photometric monitoring of young NGC 2264 cluster members using the Spitzer Infrared Array Camera (IRAC; Fazio et al. 2004) and the Convection, Rotation and Planetary Transits satellite (CoRoT; Baglin et al. 2006) simultaneously. Thirteen other telescopes monitored the region at different times concurrently with (or closely in time to) the primary Spitzer and CoRoT joint campaign. The CSI 2264 project is described in detail in Cody et al. (2014). This table contains CoRoT light curves for objects that are very likely NGC 2264 members (using the criteria described in Cody et al. 2014). There are many rows for each object, because each object has many epochs of data. There are 9 columns in this table, as follows. Columns 7, 8, and 9 (the IRAC excess flag and the light curve types) are duplications of information found in the Object Table, but are repeated here to make it easy for users to, e.g., pull out all of the light curves of a specific type.
3438. CSI2264 Object Table
ID:
ivo://irsa.ipac/Spitzer/Catalog/CSI2264/CSI2264Obj
Title:
CSI2264 Object Table
Short Name:
CSI2264 Obj
Date:
01 Oct 2018 20:27:17
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The CSI 2264 project performed photometric monitoring of young NGC 2264 cluster members using the Spitzer Infrared Array Camera (IRAC; Fazio et al. 2004) and the Convection, Rotation and Planetary Transits satellite (CoRoT; Baglin et al. 2006) simultaneously. Thirteen other telescopes monitored the region at different times concurrently with (or closely in time to) the primary Spitzer and CoRoT joint campaign. The CSI 2264 project is described in detail in Cody et al. (2014). The Object Table contains one line per object, and covers all of the objects in the greater NGC 2264 region, not just those that have light curves or are members.
3439. CSIRO ASKAP Science Data Archive Cone Search Service
ID:
ivo://au.csiro/casda/SCS
Title:
CSIRO ASKAP Science Data Archive Cone Search Service
Short Name:
CSIRO ASKAP Cone
Date:
01 Dec 2023 14:46:51
Publisher:
CSIRO
Description:
Cone search service for querying catalogues from ASKAP radio astronomy observations
3440. CSIRO Parkes Pulsar Data Archive Cone Search Service
ID:
ivo://au.csiro/psrda/ATNF_Pulsar_SCS
Title:
CSIRO Parkes Pulsar Data Archive Cone Search Service
Short Name:
CSIRO Pulsar SCS
Date:
27 Jun 2018 15:26:24
Publisher:
CSIRO
Description:
Repository of pulsar observations made at the Parkes, Australia radio telescope

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