We observed 64 newly identified galactic bulge planetary nebulae in the radio continuum at 3 and 6 cm with the Australia Telescope Compact Array. We present their radio images, positions, flux densities, and angular sizes. The survey appears to have detected a larger ratio of more extended planetary nebulae with low surface brightness than in previous surveys. We calculated their distances according to Van de Steene & Zijlstra (1995A&A...293..541V). We find that most of the new sample is located on the near side around the galactic center and closer in than the previously known bulge PNe. Based on H{alpha} images and spectroscopic data, we calculated the total H{alpha} flux. We compare this flux value with the radio flux density and derive the extinction. We confirm that the distribution of the extinction values around the galactic center rises toward the center, as expected.
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.
We have undertaken a survey of molecular lines in the 3mm band toward 57 young stellar objects using the Australia Telescope National Facility Mopra 22m radio telescope. The target sources were young stellar objects with active outflows (extended green objects (EGOs)) newly identified from the GLIMPSE II survey. We observe a high detection rate (50%) of broad line wing emission in the HNC and CS thermal lines, which combined with the high detection rate of class I methanol masers toward these sources (reported in Paper I, Cat. J/ApJS/206/9) further demonstrates that the GLIMPSE II EGOs are associated with outflows. The physical and kinematic characteristics derived from the 3mm molecular lines for these newly identified EGOs are consistent with these sources being massive young stellar objects with ongoing outflow activity and rapid accretion. These findings support our previous investigations of the mid-infrared properties of these sources and their association with other star formation tracers (e.g., infrared dark clouds, methanol masers and millimeter dust sources) presented in Paper I. The high detection rate (64%) of the hot core tracer CH_3_CN reveals that the majority of these new EGOs have evolved to the hot molecular core stage. Comparison of the observed molecular column densities with predictions from hot core chemistry models reveals that the newly identified EGOs from the GLIMPSE II survey are members of the youngest hot core population, with an evolutionary time scale of the order of 10^3^yr.
We have developed a new needlet-based method to detect point sources in cosmic microwave background (CMB) maps and have applied it to the Wilkinson Microwave Anisotropy Probe (WMAP) 7 year data. We use both the individual frequency channels as well as internal templates, the latter being the difference between pairs of frequency channels and hence having the advantage that the CMB component is eliminated. Using the area of the sky outside the Kq85 galactic mask, we detect a total of 2102 point sources at the 5{sigma} level in either the frequency maps or the internal templates. Of these, 1116 are detected either at 5{sigma} directly in the frequency channels or at 5{sigma} in the internal templates and >=3{sigma} at the corresponding position in the frequency channels. Of the 1116 sources, 603 are detections that have not been reported so far in WMAP data. We have made a catalog of these sources available with position and flux estimated in the WMAP channels where they are seen. In total, we identified 1029 of the 1116 sources with counterparts at 5GHz and 69 at other frequencies.
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.
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.
Using the NVSS radio catalog, we have searched for radio emission from 4079 quasars taken from the 1996 version of the Veron-Cetty & Veron [ESO Scientific Report No.X (1996, Cat. <VII/188>)] quasar catalog. The comparison resulted in the positive detection of radio emission from 799 quasars of these, 168 are new radio detections. Examination of the radio luminosities shows a dramatic increase in 9 the fraction of radio-loud quasars from the current epoch to z=0.5 and a gradual decline beyond z=1.0. Inspection of the radio-loud fraction as a function of MB shows little dependence fainter than M_B_=-29.5.
New Reference Frame defined by Extragalactic Radio Source
Short Name:
I/218
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the annex to Resolution B5 of the XXII Assembly of the IAU. This list of extragalactic objects identifies sources which define the new conventional celestial reference frame together with candidate sources which may, at some future date, be added or replace the defining sources. The text of the resolution has been quoted below. The list is available as the original latex file or as an ascii file.
Faraday rotation provides a valuable tracer of magnetic fields in the interstellar medium; catalogs of Faraday rotation measures provide key observations for studies of the Galactic magnetic field. We present a new catalog of rotation measures derived from the Canadian Galactic Plane Survey, covering a large region of the Galactic plane spanning 52{deg}<l<192{deg}, -3{deg}<b<5{deg}, along with northern and southern latitude extensions around l~105{deg}. We have derived rotation measures for 2234 sources (4 of which are known pulsars), 75% of which have no previous measurements, over an area of approximately 1300deg^2^. These new rotation measures increase the measurement density for this region of the Galactic plane by a factor of 2.
We present an expanded sample of low-mass black holes (BHs) found in galactic nuclei. Using standard virial mass techniques to estimate BH masses, we select from the Fourth Data Release of the Sloan Digital Sky Survey all broad-line active galaxies with masses <2x10^6^M_{sun}_ BHs in this mass regime provide unique tests of the relationship between BHs and galaxies, since their late-type galaxy hosts do not necessarily contain classical bulges. Furthermore, they provide observational analogs of primordial seed BHs and are expected, when merging, to provide strong gravitational signals for future detectors such as LISA. From our preliminary sample of 19, we have increased the total sample by an order of magnitude to 174, as well as an additional 55 (less secure) candidates.
