- ID:
- ivo://CDS.VizieR/J/A+A/319/33
- Title:
- Identification of X-ray sources around Seyferts
- Short Name:
- J/A+A/319/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Excess numbers of X-ray sources around bright Seyfert galaxies have been demonstrated with significances of association up to 7.4-sigma (Radecke, 1997A&A...319...18R). The optical identification of these sources is shown here to be predominantly blue stellar objects (BSO's) of which some are already catalogued as quasars. Excluding the two brightest Seyferts, a subset of 24 with apparent magnitudes between 8.04<=B_T_^o,i^<=12.90mag. show a minimum excess of >46 bright X-ray sources. These excess X-ray sources are generally distributed between 10'<r<40' and 12 of the Seyferts show conspicuous pairs of X-ray sources across their active nuclei. Additional pairing and alignment of sources is seen for the remaining Seyferts. Among the paired X-ray sources, 53 have been identified as BSO's. Some double and multiple BSO's have been identified which are candidates for groups and associations of quasars. Some groups are well aligned and some centered on small blue galaxies. Four previously known BL Lac objects fall close enough to the Seyferts in this sample to confirm, at a significance level of 1-2x10^-9^, a previously reported association of BL Lac objects with bright, low redshift galaxies.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/143/277
- Title:
- IRAS 1Jy sample of ultraluminous galaxies. I.
- Short Name:
- J/ApJS/143/277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An imaging survey of the IRAS 1Jy sample of 118 ultraluminous infrared galaxies was conducted at optical (R) and near-infrared (K') wavelengths using the University of Hawaii 2.2 m telescope. The methods of observation and data reduction are described. An R and K' atlas of the entire sample is presented along with some of the basic astrometric and photometric parameters derived from these images. A more detailed analysis of these data is presented in a companion paper (Veilleux et al., 2002, Cat. <J/ApJS/143/315>).
- ID:
- ivo://CDS.VizieR/J/A+A/633/A127
- Title:
- Jet-driven outflow in ESO 420-G13
- Short Name:
- J/A+A/633/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A prominent jet-driven outflow of CO(2-1) molecular gas is found along the kinematic minor axis of the Seyfert 2 galaxy ESO 420-G13, at a distance of 340-600pc from the nucleus. The wind morphology resembles a characteristic funnel shape, formed by a highly collimated filamentary emission at the base, likely tracing the jet propagation through a tenuous medium, until a bifurcation point at 440pc where the jet hits a dense molecular core and shatters, dispersing the molecular gas into several clumps and filaments within the expansion cone. We also trace the jet in ionised gas within the inner ~340pc using the [NeII]12.8um line emission, where the molecular gas follows a circular rotation pattern. The wind outflow carries a mass of ~8x10^6^M_{sun}_ at an average wind projected speed of ~160km/s, which implies a mass outflow rate of ~14M_{sun}_/yr. Based on the structure of the outflow and the budget of energy and momentum, we discard radiation pressure from the active nucleus, star formation, and supernovae as possible launching mechanisms. ESO 420-G13 is the second case after NGC 1377 where the presence of a previously unknown jet is revealed due to its interaction with the interstellar medium, suggesting that unknown jets in feeble radio nuclei might be more common than expected. Two possible jet-cloud configurations are discussed to explain the presence of an outflow at such distance from the AGN. The outflowing gas will likely not escape, thus a delay in the star formation rather than quenching is expected from this interaction, while the feedback effect would be confined within the central few hundred parsecs of the galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/130/2571
- Title:
- KISS H{alpha}-selected survey list 3
- Short Name:
- J/AJ/130/2571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The KPNO International Spectroscopic Survey (KISS) is an objective-prism survey designed to detect extragalactic emission-line objects. It combines many of the features of previous slitless spectroscopic surveys with the advantages of modern CCD detectors and is the first purely digital objective-prism survey for emission-line galaxies (ELGs). Here we present the third list of ELG candidates selected from our red spectral data, which cover the wavelength range 6400-7200{AA}. In most cases, the detected emission line is H{alpha}. The current survey list covers the region of the NOAO Deep Wide Field Survey (NDWFS). This survey covers two fields; the first is 3{deg}x3{deg} and located at RA=14h30m, DE=34{deg}30' (B1950.0), and the second is 2.3{deg}x4.0{deg} and centered at RA=2h7m30s, DE=-4{deg}44'. A total area of 19.65deg^2^ is covered by the KISS data. A total of 261 candidate emission-line objects have been selected for inclusion in the survey list (13.3deg^-2^). We tabulate accurate coordinates and photometry for each source, as well as estimates of the redshift, emission-line flux, and line equivalent width based on measurements of the digital objective-prism spectra. The properties of the KISS ELGs are examined using the available observational data.
- ID:
- ivo://CDS.VizieR/J/AJ/121/66
- Title:
- KISS H{alpha} survey list 1
- Short Name:
- J/AJ/121/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The KPNO International Spectroscopic Survey (KISS) is a new objective-prism survey for extragalactic emission-line objects. It combines many of the features of previous slitless spectroscopic surveys with the advantages of modern CCD detectors and is the first purely digital objective-prism survey for emission-line galaxies. Here we present the first list of emission-line galaxy candidates selected from our red spectral data, which cover the spectral range 6400 to 7200{AA}. In most cases, the detected emission line is H{alpha}. The current survey list covers a 1{deg}-wide strip located at {delta}= 29{deg} 30' (B1950.0) and spanning the right ascension range 12h 15m to 17h 0m. An area of 62.2{deg}^2^ is covered. A total of 1128 candidate emission-line objects have been selected for inclusion in the survey list (18.1{deg}^-2^). We tabulate accurate coordinates and photometry for each source, as well as estimates of the redshift and emission-line flux and equivalent width based on measurements of the digital objective-prism spectra. The properties of the KISS emission-line galaxies are examined using the available observational data.
- ID:
- ivo://CDS.VizieR/J/AJ/127/1943
- Title:
- KISS H{alpha} survey list 2
- Short Name:
- J/AJ/127/1943
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The KPNO International Spectroscopic Survey (KISS) is an objective-prism survey for extragalactic emission-line objects. It combines many of the features of previous slitless spectroscopic surveys with the advantages of modern CCD detectors and is the first purely digital objective-prism survey for emission-line galaxies. Here we present the second list of emission-line galaxy candidates selected from our red spectral data, which cover the wavelength range 6400 to 7200{AA}. In most cases, the detected emission line is H{alpha}. The current survey list covers a 1.6{deg}-wide strip located at {delta}=43{deg}30'(B1950) and spans the right ascension range 11h55m to 16h15m. The survey strip runs through the center of the Bootes void and has enough depth to adequately sample the far side of the void. An area of 65.8deg^2^ is covered. A total of 1029 candidate emission-line objects have been selected for inclusion in the survey list (15.6deg^-2^). We tabulate accurate coordinates and photometry for each source, as well as estimates of the redshift and emission-line flux and equivalent width based on measurements of the digital objective-prism spectra. The properties of the KISS emission-line galaxies are examined using the available observational data. Although the current survey covers only a modest fraction of the total volume of the Bootes void, we catalog at least 12 objects that appear to be located within the void. Only one of these objects has been recognized previously as a void galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/123/1292
- Title:
- KISS III. [O III]-selected survey list
- Short Name:
- J/AJ/123/1292
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The KPNO International Spectroscopic Survey (KISS) is an objective-prism survey for extragalactic emission-line objects. It combines many of the features of previous slitless spectroscopic surveys with the advantages of modern CCD detectors, and it is the first purely digital objective-prism survey for emission-line galaxies. Here we present the first list of emission-line galaxy candidates selected from our blue spectral data, which cover the wavelength range 4800-5500{AA}. In most cases, the detected emission line is [O III] {lambda}5007. The current survey list covers a 1{deg}-wide strip located at {delta}=29{deg}30' (B1950.0) and spanning the right ascension range 8h30min to 17h0min. An area of 116.6d{deg}^2^ is covered. A total of 223 candidate emission-line objects have been selected for inclusion in the survey list (1.91{deg}^-2^). We tabulate accurate coordinates and photometry for each source, as well as estimates of the redshift, emission-line flux, and equivalent width based on measurements of the digital objective-prism spectra. The median apparent magnitude of the sample is B=18.2, and galaxies with redshifts approaching z=0.1 are detected.
- ID:
- ivo://CDS.VizieR/J/ApJ/871/108
- Title:
- Lick AGN monitoring project 2011: V band
- Short Name:
- J/ApJ/871/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In Spring 2011, the Lick AGN Monitoring Project observed a sample of 15 bright, nearby Seyfert 1 galaxies in the V band as part of a reverberation mapping campaign. The observations were taken at six ground-based telescopes, including the West Mountain Observatory 0.91m telescope, the 0.76m Katzman Automatic Imaging Telescope, 0.6m Super-LOTIS (Livermore Optical Transient Imaging System) at Kitt Peak, the Palomar 60inch telescope, and the 2m Faulkes telescopes North and South. The V-band light curves measure the continuum variability of our sample of Seyferts on an almost daily cadence for 2-3 months. We use image-subtraction software to isolate the variability of the Seyfert nucleus from the constant V-band flux of the host galaxy for the most promising targets, and we adopt standard aperture photometry techniques for the targets with smaller levels of variability. These V-band light curves will be used, with measurements of the broad emission line flux, to measure supermassive black hole masses and to constrain the geometry and dynamics of the broad-line region through dynamical modeling techniques.
- ID:
- ivo://CDS.VizieR/J/ApJ/793/82
- Title:
- LOFAR Bootes and 3C295 field sources
- Short Name:
- J/ApJ/793/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Low Frequency Array (LOFAR) Low Band observations of the Bootes and 3C 295 fields. Our images made at 34, 46, and 62 MHz reach noise levels of 12, 8, and 5 mJy/beam, making them the deepest images ever obtained in this frequency range. In total, we detect between 300 and 400 sources in each of these images, covering an area of 17-52 deg^2^. From the observations, we derive Euclidean-normalized differential source counts. The 62 MHz source counts agree with previous GMRT 153 MHz and Very Large Array 74 MHz differential source counts, scaling with a spectral index of -0.7. We find that a spectral index scaling of -0.5 is required to match up the LOFAR 34 MHz source counts. This result is also in agreement with source counts from the 38 MHz 8C survey, indicating that the average spectral index of radio sources flattens toward lower frequencies. We also find evidence for spectral flattening using the individual flux measurements of sources between 34 and 1400 MHz and by calculating the spectral index averaged over the source population. To select ultra-steep spectrum ({alpha}<-1.1) radio sources that could be associated with massive high-redshift radio galaxies, we compute spectral indices between 62 MHz, 153 MHz, and 1.4 GHz for sources in the Bootes field. We cross-correlate these radio sources with optical and infrared catalogs and fit the spectral energy distribution to obtain photometric redshifts. We find that most of these ultra-steep spectrum sources are located in the 0.7<~z<~2.5 range.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A69
- Title:
- LOFAR 143MHz images of 3C 236
- Short Name:
- J/A+A/628/A69
- Date:
- 23 Mar 2022 16:28:49
- Publisher:
- CDS
- Description:
- We have examined the giant radio galaxy 3C 236 using LOFAR at 143MHz down to an angular resolution of 7 arcseconds, in combination with observations at higher frequencies. We used the low frequency data to derive spectral index maps with the highest resolution yet at these low frequencies. We confirm a previous detection of an inner hotspot in the north-west lobe and for the first time observe that the south-east lobe hotspot is in fact a triple hotspot, which may point to an intermittent source activity. Also, the spectral index map of 3C 236 shows that the spectral steepening at the inner region of the northern lobe is prominent at low frequencies. The outer regions of both lobes show spectral flattening, in contrast with previous high frequency studies. We derive spectral age estimates for the lobes, as well as particle densities of the IGM at various locations. We propose that the morphological differences between the lobes are driven by variations in the ambient medium density as well as the source activity history.
