- ID:
- ivo://CDS.VizieR/J/MNRAS/382/1552
- Title:
- Multiwavelength study of nearby galaxy nuclei
- Short Name:
- J/MNRAS/382/1552
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and infrared broad-band images, radio maps, and optical spectroscopy for the nuclear region of a sample of nearby galaxies. The galaxies have been drawn from a complete volume-limited sample for which we have already presented X-ray imaging. We modelled the stellar component of the spectroscopic observations to determine the star formation history of our targets. Diagnostic diagrams were used to classify the emission-line spectra and determine the ionizing mechanism driving the nuclear regions. All those sources classified as active galactic nuclei present small Eddington ratios (~10^-3^-10^-6^), implying a very slow growth rate of their black holes. We finally investigate the relative numbers of active and normal nuclei as a function of host galaxy luminosity and find that the fraction of active galaxies slowly rises as a function of host absolute magnitude in the MB~-12 to -22 range.
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- ID:
- ivo://CDS.VizieR/J/ApJ/755/47
- Title:
- Murchison Widefield Array 110-200MHz observations
- Short Name:
- J/ApJ/755/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Murchison Widefield Array (MWA) is a new low-frequency, wide field-of-view radio interferometer under development at the Murchison Radio-astronomy Observatory in Western Australia. We have used a 32 element MWA prototype interferometer (MWA-32T) to observe two 50{deg} diameter fields in the southern sky, covering a total of ~2700deg^2^, in order to evaluate the performance of the MWA-32T, to develop techniques for epoch of reionization experiments, and to make measurements of astronomical foregrounds. We developed a calibration and imaging pipeline for the MWA-32T, and used it to produce ~15' angular resolution maps of the two fields in the 110-200MHz band. We perform a blind source extraction using these confusion-limited images, and detect 655 sources at high significance with an additional 871 lower significance source candidates. We compare these sources with existing low-frequency radio surveys in order to assess the MWA-32T system performance, wide-field analysis algorithms, and catalog quality. Our source catalog is found to agree well with existing low-frequency surveys in these regions of the sky and with statistical distributions of point sources derived from Northern Hemisphere surveys; it represents one of the deepest surveys to date of this sky field in the 110-200MHz band.
- ID:
- ivo://CDS.VizieR/VIII/61
- Title:
- NAIC 611 MHz Survey Source List
- Short Name:
- VIII/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 1000 foot Arecibo reflector was used with a multiple feed system to map the region 0h < RA < 12h, -2d < DEC < +18d at 611 MHz. The observations were made in meridian transit mode using an array of ten line feeds with the electric polarization vector in the east-west plane. The beam power pattern of each feed was approximately Gaussian and circulary symmetric with a half power beam width of about 12.6 arcmin. A source list was produced containing fluxes and positions of 3118 radio sources stronger than 0.35 Jy. The source list is complete for strong, unresolved sources. However it is not intended to be complete for objects highly resolved by the 12.6 arcmin beamsize. The list's lower limit of 0.35 Jy is about 5 times the average sky confusion. The survey was calibrated to the KPW (Kellermann, Pauliny-Toth, and Williams 1969ApJ...157....1K) flux scale. The secondary calibrators were ten sources measured at Arecibo at 606 MHz based on the KPW scale (Condon, Niell and Jauncey 1971). Marked by an asterisk in Table 2, these sources were too few to be used alone to calibrate all of the declination strips. Since a more complete list of good calibration sources did not exist at 611 MHz, the fluxes of 159 additional sources were independently measured accurate to about 7 percent at Arecibo in the Fall of 1973. Table 2 gives their assigned fluxes. These sources were tied to the KPW scale through the ten secondary calibrators.
- ID:
- ivo://CDS.VizieR/J/AJ/124/3042
- Title:
- Narrow-line Seyfert 1 galaxies from SDSS EDR
- Short Name:
- J/AJ/124/3042
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 150 narrow-line Seyfert 1 galaxies (NLS1's) found within the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR) (Stoughton et al., 2002AJ....123..485S), only two of which were previously identified as such. This substantially increases the known number of NLS1's and provides a basic method by which to identify many more with subsequent releases of SDSS data. With its large size and homogeneous, well-defined selection criteria, this sample will help alleviate two major problems that have plagued NLS1 research in the past; namely, their relative rarity and significant differences in selection algorithms between the known samples. Forty-five of these SDSS-selected NLS1's are detected at energies of 0.1-2keV in the ROSAT All-Sky Survey (RASS) and are found to have ultrasoft X-ray spectra with photon indices of {Gamma}>~2, in agreement with previous results for NLS1's. However, about 10-20 of those NLS1's that were not detected by ROSAT have optical properties very similar to the detected objects and so should also have been detected by the RASS. This may be due to either significant intrinsic absorption in many NLS1's, or a significant subclass of NLS1's that have uncharacteristic, intrinsically flatter (hence harder) X-ray spectral energy distributions.
- ID:
- ivo://CDS.VizieR/J/PASP/120/339
- Title:
- Nasu Radio-Transient Search Project
- Short Name:
- J/PASP/120/339
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of two 1.4GHz radio surveys of a +32{deg}<DE<+42{deg} area with four interferometers in the Nasu Radio-Transient Search Project. The observable area was 7.0% of the whole sky. The surveys were carried out between 2004 and 2005. All observed interferometric data were transformed to color images to construct color atlases of the 1.4GHz sky. From these atlases, 144 radio sources were detected by comparison with the 1.4GHz NRAO VLA Sky Survey Catalog, excluding the Cygnus region. The observed data will be used in a transient search alert system.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A110
- Title:
- N131 bubble CO (3-2), (2-1) and (1-0) observations
- Short Name:
- J/A+A/631/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- N131 is a typical infrared dust bubble showing an expanding ringlike shell. We study what kinds of CO line ratios can be used to trace the interaction in the expanding bubble. We carry out new CO (3-2) observations towards bubble N131 using JCMT 15-m telescope, and derive line ratios by combining with our previous CO (2-1) and CO (1-0) data from IRAM 30-m observations. To trace the interaction between the molecular gas and the ionized gas in the HII region, we use RADEX to model the dependence of CO line ratios on kinetic temperature and H_2_ volume density, and examine the abnormal line ratios based on other simulations. We present CO (3-2), CO (2-1), and CO (1-0) integrated intensity maps convolved to the same angular resolution (22.5"). The three different CO transition maps show apparently similar morphology. The line ratios of W_CO_(3-2)/W_CO_(2-1) mostly range from 0.2 to 1.2 with a median of 0.54+/-0.12, while the line ratios of W_CO_(2-1)/W_CO_(1-0) range from 0.5 to 1.6 with a median of 0.84+/-0.15. The high CO line ratios W_CO_(3-2)/W_CO_(2-1)>0.8 and W_CO_(2-1)/W_CO_(1-0)>1.2 are beyond the threshold predicted by numerical simulations based on the assumed density-temperature structure for the inner rims of ringlike shell, where are the compressed areas in bubble N131. These high CO integrated intensity ratios, such as W_CO_(3-2)/W_CO_(2-1)>0.8 and W_CO_(2-1)/W_CO_(1-0)>1.2, can be used as a tracer of gas compressed regions with a relatively high temperature and density. This further suggests that the non-Gaussian part of the line-ratio distribution can be used to trace the interaction between the molecular gas and the hot gas in the bubble.
- ID:
- ivo://CDS.VizieR/VIII/82
- Title:
- 2nd Epoch Molonglo Galactic Plane Survey (MGPS-2)
- Short Name:
- VIII/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The MGPS-2 (second epoch Molonglo Galactic Plane Survey) was carried out with the Molonglo Observatory Synthesis Telescope at a frequency of 843MHz and with a restoring beam of 45"x45"csd|{delta}|, making it he highest resolution large scale radio survey of the southern Galactic plane. It covers the range |b|<10{deg} and 245<l<365{deg}; it is the Galactic counterpart to the SUMSS (Cat. VIII/81) which covers the southern sky ({delta}<-30{deg}, |b|>10{deg}). This catalogue (15-Aug-2007) consists of 48850 compact sources, made by fitting elliptical gaussians in the MGPS-2 mosaics to a limiting peak brightness of 10mJy/beam. We used a custom method (described in the associated publication) to remove extended sources from the catalogue. Positions in the catalogue are accurate to 1-2". See http://www.astrop.physics.usyd.edu.au/mosaics for access to the mosaic images.
- ID:
- ivo://CDS.VizieR/J/ApJS/206/17
- Title:
- New gamma-ray blazar candidates in the 3PBC
- Short Name:
- J/ApJS/206/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We searched for {gamma}-ray blazar candidates among the 382 unidentified hard X-ray sources of the third Palermo BAT Catalog (3PBC) obtained from the analysis of 66 months of Swift Burst Alert Telescope (BAT) survey data and listing 1586 sources. We adopted a recently developed association method based on the peculiar infrared colors that characterize the {gamma}-ray blazars included in the second catalog of active galactic nuclei detected by the Fermi Large Area Telescope. We used this method exploiting the data of the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) to establish correspondences between unidentified 3PBC sources and WISE {gamma}-ray blazar candidates located within the BAT positional uncertainty region at a 99% confidence level. We obtained a preliminary list of candidates for which we analyzed all the available data in the Swift archive to complement the information in the literature and in the radio, infrared, and optical catalogs with the information on their optical-UV and soft X-ray emission. Requiring the presence of radio and soft X-ray counterparts consistent with the infrared positions of the selected WISE sources, as well as a blazar-like radio morphology, we finally obtained a list of 24 {gamma}-ray blazar candidates.
- ID:
- ivo://CDS.VizieR/J/ApJS/170/108
- Title:
- NEWPS_5{sigma}_ source catalogue from WMAP
- Short Name:
- J/ApJS/170/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the MHW2 filter to obtain estimates of the flux densities at the WMAP frequencies of a complete sample of 2491 sources, mostly brighter than 500mJy at 5GHz, distributed over the whole sky excluding a strip around the Galactic equator (|b|<=5{deg}). After having detected 933 sources at the >=3{sigma} level in the MHW2 filtered maps-our New Extragalactic WMAP Point Source Catalogue (NEWPS_3{sigma}_)-we are left with 381 sources at >=5{sigma} in at least one WMAP channel, 369 of which constitute our NEWPS_5{sigma}_ catalog. It is remarkable to note that 98 (i.e., 26%) sources detected at are "new," they are not present in the WMAP catalog.
- ID:
- ivo://CDS.VizieR/J/MNRAS/359/1524
- Title:
- 10 new pulsars in Arecibo drift-scan survey
- Short Name:
- J/MNRAS/359/1524
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a 430-MHz survey for pulsars conducted during the upgrade to the 305-m Arecibo radio telescope. Our survey covered a total of 1147deg^2^ of sky using a drift-scan technique. We detected 33 pulsars, 10 of which were not known prior to the survey observations. The highlight of the new discoveries is PSR J0407+1607, which has a spin period of 25.7ms, a characteristic age of 1.5Gyr and is in a 1.8-yr orbit about a low-mass (>0.2M) companion. The long orbital period and small eccentricity (e=0.0009) make the binary system an important new addition to the ensemble of binary pulsars suitable to test for violations of the strong equivalence principle. We also report on our initially unsuccessful attempts to detect optically the companion to J0407+1607, which imply that its absolute visual magnitude is >12.1. If, as expected on evolutionary grounds, the companion is an He white dwarf, our non-detection implies a cooling age of least 1Gyr.
