- ID:
- ivo://CDS.VizieR/VII/16
- Title:
- Reference Catalogue of Bright Galaxies
- Short Name:
- VII/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Reference Catalogue of Bright Galaxies lists for each entry the following information: NGC number, IC number, or A number; A, B, or C designation; B1950.0 positions, position at 100 year precession; galactic and supergalactic positions; revised morphological type and source; type and color class in Yerkes list 1 and 2; Hubble-Sandage type; revised Hubble type according to Holmberg; logarithm of mean major diameter (log D) and ratio of major to minor diameter (log R) and their weights; logarithm of major diameter; sources of the diameters; David Dunlap Observatory type and luminosity class; Harvard photographic apparent magnitude; weight of V, B-V(0), U-B(0); integrated magnitude B(0) and its weight in the B system; mean surface brightness in magnitude per square minute of arc and sources for the B magnitude; mean B surface brightness derived from corrected Harvard magnitude; the integrated color index in the standard B-V system; "intrinsic" color index; sources of B-V and/or U-B; integrated color in the standard U-B system; observed radial velocity in km/sec; radial velocity corrected for solar motion in km/sec; sources of radial velocities; solar motion correction; and direct photographic source. The catalog was created by concatenating four files side by side.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/217/2
- Title:
- Refined associations of Fermi/LAT sources
- Short Name:
- J/ApJS/217/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Fermi-Large Area Telescope (LAT) First Source Catalog (1FGL) was released in 2010 February and the Fermi-LAT 2-Year Source Catalog (2FGL) appeared in 2012 April, based on data from 24 months of operation. Since they were released, many follow up observations of unidentified {gamma}-ray sources have been performed and new procedures for associating {gamma}-ray sources with potential counterparts at other wavelengths have been developed. Here we review and characterize all of the associations as published in the 1FGL and 2FGL catalogs on the basis of multifrequency archival observations. In particular, we located 177 spectra for the low-energy counterparts that were not listed in the previous Fermi catalogs, and in addition we present new spectroscopic observations of eight {gamma}-ray blazar candidates. Based on our investigations, we introduce a new counterpart category of "candidate associations" and propose a refined classification for the candidate low-energy counterparts of the Fermi sources. We compare the 1FGL-assigned counterparts with those listed in 2FGL to determine which unassociated sources became associated in later releases of the Fermi catalogs. We also search for potential counterparts to all of the remaining unassociated Fermi sources. Finally, we prepare a refined and merged list of all of the associations of 1FGL plus 2FGL that includes 2219 unique Fermi objects. This is the most comprehensive and systematic study of all the associations collected for the {gamma}-ray sources available to date. We conclude that 80% of the Fermi sources have at least one known plausible {gamma}-ray emitter within their positional uncertainty regions.
- ID:
- ivo://CDS.VizieR/J/MNRAS/422/3268
- Title:
- Relation between X-ray and optical spectra
- Short Name:
- J/MNRAS/422/3268
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this second paper in a series of three, we study the properties of the various emission features and underlying continuum in the optical spectra of type 1 active galactic nuclei (AGNs) by using the unobscured hard X-ray emission as a diagnostic. We introduce the use of the "correlation spectrum technique" (CST) for the first time. We use this to show the strength of the correlation between the hard X-ray luminosity and each wavelength of the optical spectrum. This shows that for broad-line Seyfert 1 galaxies all the strong emission lines (the broad component of H{alpha} and H{beta}, [NeIII] {lambda}{lambda}3869/3967, [OI] {lambda}{lambda}6300/6364, [OII] {lambda}{lambda}3726/3729 and [OIII] {lambda}{lambda}4959/5007) and the optical underlying continuum all strongly correlate with the hard X-ray emission. In contrast, the narrow-line Seyfert 1 galaxies show a stronger correlation in the optical continuum but a weaker correlation in the lines.
- ID:
- ivo://CDS.VizieR/J/other/Sci/338.1445
- Title:
- Relativistic jets from black hole systems
- Short Name:
- J/other/Sci/338.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Black holes generate collimated, relativistic jets, which have been observed in {gamma}-ray bursts (GRBs), microquasars, and at the center of some galaxies [active galactic nuclei (AGN)]. How jet physics scales from stellar black holes in GRBs to the supermassive ones in AGN is still unknown. Here, we show that jets produced by AGN and GRBs exhibit the same correlation between the kinetic power carried by accelerated particles and the {gamma}-ray luminosity, with AGN and GRBs lying at the low- and high-luminosity ends, respectively, of the correlation. This result implies that the efficiency of energy dissipation in jets produced in black hole systems is similar over 10 orders of magnitude in jet power, establishing a physical analogy between AGN and GRBs.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2357
- Title:
- Relativistic jets in the RRFID database
- Short Name:
- J/AJ/133/2357
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an analysis of relativistic jet apparent speeds from VLBI images in the Radio Reference Frame Image Database (RRFID). The images are snapshot VLBI images at 8 and 2GHz using the VLBA, plus up to 10 additional antennas that provide global VLBI coverage. We have analyzed the 8GHz images from the first 5 years of the database (1994-1998), for all sources observed at three or more epochs during this time range. This subset comprises 966 images of 87 sources. The sources in this subset have an average of 11 epochs of observation over the years 1994-1998, with the best-observed sources having 19 epochs. About half of the sources in this RRFID kinematic survey have not been previously studied with multi-epoch VLBI observations. We have measured apparent speeds for a total of 184 jet components in 77 sources, of which the best-measured 94 component speeds in 54 sources are used in the final analysis.
- ID:
- ivo://CDS.VizieR/J/ApJ/758/84
- Title:
- Relativistic jets in the RRFID database. II. 10yr
- Short Name:
- J/ApJ/758/84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze blazar jet apparent speeds and accelerations from the RDV series of astrometric and geodetic very long baseline interferometry (VLBI) experiments. From these experiments, we have produced and analyzed 2753 global VLBI images of 68 sources at 8GHz with a median beam size of 0.9 milliarcseconds (mas) and a median of 43 epochs per source. From this sample, we analyze the motions of 225 jet components in 66 sources. The distribution of the fastest measured apparent speed in each source has a median of 8.3c and a maximum of 44c. Sources in the 2FGL Fermi LAT catalog display higher apparent speeds than those that have not been detected. On average, components farther from the core in a given source have significantly higher apparent speeds than components closer to the core; for example, for a typical source, components at ~3mas from the core (~15pc projected at z~0.5) have apparent speeds about 50% higher than those of components at ~1mas from the core (~5pc projected at z~0.5). We measure accelerations of components in orthogonal directions parallel and perpendicular to their average velocity vector. Parallel accelerations have significantly larger magnitudes than perpendicular accelerations, implying that observed accelerations are predominantly due to changes in the Lorentz factor (bulk or pattern) rather than projection effects from jet bending. Positive parallel accelerations are significantly more common than negative ones, so the Lorentz factor (bulk or pattern) tends to increase on the scales observed here. Observed parallel accelerations correspond to modest source frame increases in the bulk or pattern Lorentz factor.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A8
- Title:
- Resolved jet of 3C 273 at 150 MHz
- Short Name:
- J/A+A/658/A8
- Date:
- 02 Feb 2022 13:25:19
- Publisher:
- CDS
- Description:
- Since its discovery in 1963, 3C 273 has become one of the most widely studied quasars with investigations spanning the electromagnetic spectrum. While much has therefore been discovered about this historically notable source, its low-frequency emission is far less well understood. Observations in the MHz regime have traditionally lacked the resolution required to explore small-scale structures, such as knots and diffuse jet emission, that are key to understanding the processes that result in the observed emission. Advances in the processing of LOFAR international baseline data have now removed this limitation, providing the opportunity to explore this key area for the first time. In this paper we use the first sub-arcsecond images of 3C 273 at MHz frequencies to investigate the morphology of the compact jet structures and the processes that result in the observed spectrum. We will determine the jet's kinetic power, place constraints on the bulk speed and inclination angle of the jets, and look for evidence of the elusive counterjet at 150MHz. Using the full complement of LOFAR's international stations (German, Poland, France, UK, Sweden), we produce 0.31x0.21 arcsec images of 3C 273 at 150MHz. Using ancillary data at GHz frequencies, we fit free-free absorption (FFA) and synchrotron self-absorption (SSA) models to each region in order to determine their validity in explaining the observed spectra. The images presented display for the first time that robust, high-fidelity imaging of low-declination complex sources is now possible with the LOFAR international baselines. We show that the main small-scale structures of 3C 273 match those seen at higher frequencies, with a tenuous detection of an extension to the outer lobe. We find that FFA and SSA models are able to describe the spectrum of the knots and, while differentiating between model types requires further observations, conclude that absorption is present in the observed emission. We determine the kinetic power of the jet to be in the range of 3.5x10^43^-1.5x10^44^erg/s which agrees with estimates made using higher frequency observations. We derive lower limits for the bulk speed and Lorentz factor of beta>0.55 and Gamma>1.2 respectively. The counter-jet remains undetected at 150MHz, placing a limit on the peak brightness of S_cj_150<40mJy/beam.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/109
- Title:
- Rest-frame optical spectra of 3<z<6 QSOs
- Short Name:
- J/ApJ/806/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the rest-frame optical spectral properties of 155 luminous quasars at 3.3<z<6.4 taken with the AKARI space telescope, including the first detection of the H{alpha} emission line as far out as z~6. We extend the scaling relation between the rest-frame optical continuum and the line luminosity of active galactic nuclei (AGNs) to the high-luminosity, high-redshift regime that has rarely been probed before. Remarkably, we find that a single log-linear relation can be applied to the 5100{AA} and H{alpha} AGN luminosities over a wide range of luminosity (10^42^<L_5100_<10^47^ergs/s) or redshift (0<z<6), suggesting that the physical mechanism governing this relation is unchanged from z=0 to 6, over five decades in luminosity. Similar scaling relations are found between the optical and the UV continuum luminosities or line widths. Applying the scaling relations to the H{beta} black hole (BH) mass (M_BH_) estimator of local AGNs, we derive the M_BH_ estimators based on the H{alpha}, MgII, and CIV lines, finding that the UV-line-based masses are overall consistent with the Balmer-line-based, but with a large intrinsic scatter of 0.40dex for the CIV estimates. Our 43 M_BH_ estimates from H{alpha} confirm the existence of BHs as massive as ~10^10^M_{sun}_ out to z~5 and provide a secure footing for previous results from MgII-line-based studies that a rapid M_BH_ growth has occurred in the early universe.
- ID:
- ivo://CDS.VizieR/J/ApJ/753/L2
- Title:
- Reverberation mapping of AGNs
- Short Name:
- J/ApJ/753/L2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Estimates of the mass of super-massive black holes (BHs) in distant active galactic nuclei (AGNs) can be obtained efficiently only through single-epoch (SE) spectra, using a combination of their broad emission line widths and continuum luminosities. Yet the reliability and accuracy of the method and the resulting mass estimates, M_BH_, remain uncertain. A recent study by Croom using a sample of Sloan Digital Sky Survey, 2dF QSO Redshift Survey, and 2dF-SDSS LRG and QSO Survey quasars suggests that line widths contribute little information about the BH mass in these SE estimates and can be replaced by a constant value without significant loss of accuracy. In this Letter, we use a sample of nearby reverberation-mapped AGNs to show that this conclusion is not universally applicable. We use the bulge luminosity (L_Bulge_) of these local objects to test how well the known M_BH_-L_Bulge_correlation is recovered when using randomly assigned line widths instead of the measured ones to estimate M_BH_. We find that line widths provide significant information about M_BH_, and that for this sample, the line width information is just as significant as that provided by the continuum luminosities. We discuss the effects of observational biases upon the analysis of Croom and suggest that the results can probably be explained as a bias of flux-limited, shallow quasar samples.
- ID:
- ivo://CDS.VizieR/J/ApJ/876/102
- Title:
- Reverberation mapping of the Seyfert Zw I 1
- Short Name:
- J/ApJ/876/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results of the first reverberation mapping campaign of I Zwicky 1 during 2014-2016, which showed unambiguous reverberations of the broad H{beta} line emission in the varying optical continuum. From analysis using several methods, we obtain a reverberation lag of {tau}_H{beta}_=37.2_-4.9_^+4.5^days. Taking a virial factor of f_BLR_=1, we find a black hole mass of M_{bullet}_=9.30_-1.38_^+1.26^x10^6^M_{sun}_ from the mean spectra. The accretion rate is estimated to be 203.9_-65.8_^+61.0^L_Edd_c^-2^, suggesting a super-Eddington accretor, where LEdd is the Eddington luminosity and c is the speed of light. By decomposing Hubble Space Telescope images, we find that the stellar mass of the bulge of its host galaxy is log(M_bulge_/M_{sun}_)=10.92+/-0.07. This leads to a black hole to bulge mass ratio of ~10^-4^, which is significantly smaller than that of classical bulges and elliptical galaxies. After subtracting the host contamination from the observed luminosity, we find that I Zw 1 follows the empirical R_BLR_{propto}L_5100_^1/2^ relation.
