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Start Over Subject radio astronomy Result Type text/xml+votable
1101. 10 new pulsars in Arecibo drift-scan survey
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.
1102. New quasar radio detections
ID:
ivo://CDS.VizieR/J/AJ/113/2000
Title:
New quasar radio detections
Short Name:
J/AJ/113/2000
Date:
21 Oct 2021
Publisher:
CDS
Description:
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.
1103. New Reference Frame defined by Extragalactic Radio Source
ID:
ivo://CDS.VizieR/I/218
Title:
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.
1104. New rotation measures from the CGPS
ID:
ivo://CDS.VizieR/J/ApJS/253/48
Title:
New rotation measures from the CGPS
Short Name:
J/ApJS/253/48
Date:
21 Oct 2021
Publisher:
CDS
Description:
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.
1105. New sample of low-mass black holes in AGN
ID:
ivo://CDS.VizieR/J/ApJ/670/92
Title:
New sample of low-mass black holes in AGN
Short Name:
J/ApJ/670/92
Date:
21 Oct 2021
Publisher:
CDS
Description:
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.
1106. New star clusters in the central plane region
ID:
ivo://CDS.VizieR/J/ApJ/856/152
Title:
New star clusters in the central plane region
Short Name:
J/ApJ/856/152
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the discovery of new star clusters in the central plane region (|l|<30{deg} and |b|<6{deg}) of the Milky Way. In order to overcome the extinction problem and the spatial limit of previous surveys, we use the Wide-field Infrared Survey Explorer (WISE) data to find clusters. We also use other infrared survey data in the archive for additional analysis. We find 923 new clusters, of which 202 clusters are embedded clusters. These clusters are concentrated toward the Galactic plane and show a symmetric distribution with respect to the Galactic latitude. The embedded clusters show a stronger concentration to the Galactic plane than the nonembedded clusters. The new clusters are found more in the first Galactic quadrant, while previously known clusters are found more in the fourth Galactic quadrant. The spatial distribution of the combined sample of known clusters and new clusters is approximately symmetric with respect to the Galactic longitude. We estimate reddenings, distances, and relative ages of the 15 class A clusters using theoretical isochrones. Ten of them are relatively old (age >800Myr) and five are young (age ~4Myr).
1107. New VLA Sky Survey (NVSS) Cat of IRAS 2 Jy Galaxies
ID:
ivo://CDS.VizieR/J/ApJ/554/803
Title:
New VLA Sky Survey (NVSS) Cat of IRAS 2 Jy Galaxies
Short Name:
J/ApJ/554/803
Date:
21 Oct 2021
Publisher:
CDS
Description:
The radio counterparts to the IRAS Redshift Survey galaxies are identified in the NRAO VLA Sky Survey (NVSS) catalog. Our new catalog of the IR flux-limited (>2 Jy at 60 micron) complete sample of 1809 galaxies lists accurate radio positions, redshifts, and 1.4 GHz radio and IRAS flux densities and luminosities.
1108. New z>=3.6 QSOs from FIRST-SDSS DR5
ID:
ivo://CDS.VizieR/J/MNRAS/391/369
Title:
New z>=3.6 QSOs from FIRST-SDSS DR5
Short Name:
J/MNRAS/391/369
Date:
21 Oct 2021
Publisher:
CDS
Description:
We aim to obtain a complete sample of redshift z>=3.6 radio quasi-stellar objects (QSOs) from the Faint Images of the Radio Sky at Twenty cm survey (FIRST) sources (S_1.4GHz_>1mJy) having star-like counterparts in the Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) photometric survey (r_AB_<=20.2). Our starting sample of 8665 FIRST-DR5 pairs includes 4250 objects with spectra in DR5, 52 of these being z>=3.6 QSOs. We found that simple supervised neural networks, trained on the sources with DR5 spectra, and using optical photometry and radio data, are very effective for identifying high-z QSOs in a sample without spectra. For the sources with DR5 spectra the technique yields a completeness (fraction of actual high-z QSOs classified as such by the neural network) of 96 per cent, and an efficiency (fraction of objects selected by the neural network as high-z QSOs that actually are high-z QSOs) of 62 per cent. Applying the trained networks to the 4415 sources without DR5 spectra we found 58 z>=3.6 QSO candidates. We obtained spectra of 27 of them, and 17 are confirmed as high-z QSOs. Spectra of 13 additional candidates from the literature and from SDSS Data Release 6 (DR6) revealed seven more z>=3.6 QSOs, giving an overall efficiency of 60 per cent (24/40).
1109. NGC 1377 ALMA CO 3-2 and 0.8mm continuum images
ID:
ivo://CDS.VizieR/J/A+A/640/A104
Title:
NGC 1377 ALMA CO 3-2 and 0.8mm continuum images
Short Name:
J/A+A/640/A104
Date:
21 Oct 2021
Publisher:
CDS
Description:
Submillimetre and millimetre line and continuum observations are important in probing the morphology, column density, and dynamics of the molecular gas and dust around obscured active galactic nuclei (AGNs) and their mechanical feedback. With very high resolution (0.02"x0.03" (2x3pc)) ALMA 345GHz observations of CO 3-2, HCO^+^ 4-3, vibrationally excited HCN 4-3 {nu}_2_=1f , and continuum we have studied the remarkable, extremely radio-quiet, molecular jet and wind of the lenticular galaxy NGC 1377. The outflow structure is resolved, revealing a 150pc long, clumpy, high-velocity (600km/s), collimated molecular jet where the molecular emission is emerging from the spine of the jet with an average diameter of 3-7pc. The jet widens to 10-15pc about 25pc from the centre, which is possibly due to jet-wind interactions. A narrow-angle (50-70), misaligned and rotating molecular wind surrounds the jet, and both are enveloped by a larger-scale CO-emitting structure at near-systemic velocity. The jet and narrow wind have steep radial gas excitation gradients and appear turbulent with high gas dispersion (>40km/s). The jet shows velocity reversals that we propose are caused by precession, or more episodic directional changes. We discuss the mechanisms powering the outflow, and we find that an important process for the molecular jet and narrow wind is likely magneto-centrifugal driving. In contrast, the large-scale CO-envelope may be a slow wind, or cocoon that stems from jet-wind interactions. An asymmetric, nuclear r~2pc dust structure with a high inferred molecular column density N(H_2_)=1.8x10^24^cm^-2^ is detected in continuum and also shows compact emission from vibrationally excited HCN. The nuclear dust emission is hot (Td>180K) and its luminosity is likely powered by a buried AGN. The lopsided structure appears to be a warped disk, which is responsible for a significant part of the nuclear obscuration and possibly formed as a result of uneven gas inflows. The dynamical mass inside r=1.4pc is estimated to 9^+2^_3_x10^6^M_{sun}_, implying that the supermassive black hole (SMBH) has a high mass with respect to the stellar velocity dispersion of NGC 1377. We suggest that the SMBH of NGC 1377 is currently in a state of moderate growth, at the end of a more intense phase of accretion and also evolving from a state of more extreme nuclear obscuration. The nuclear growth may be fuelled by low-angular momentum gas inflowing from the gas ejected in the molecular jet and wind. Such a feedback-loop of cyclic outflows and central accretion could explain why there is still a significant reservoir of molecular gas in this ageing, lenticular galaxy. A feedback-loop would be an effective process in growing the nuclear SMBH and thus would constitute an important phase in the evolution of NGC 1377. This also invites new questions as to SMBH growth processes in obscured, dusty galaxies.
1110. NGC6334 ALMA 87.6GHz continuum emission map
ID:
ivo://CDS.VizieR/J/A+A/635/A2
Title:
NGC6334 ALMA 87.6GHz continuum emission map
Short Name:
J/A+A/635/A2
Date:
21 Oct 2021
Publisher:
CDS
Description:
We aim to characterise certain physical properties of high-mass star-forming sites in the NGC6334 molecular cloud, such as the core mass function (CMF), spatial distribution of cores, and mass segregation. We used the Atacama Large Millimetre/sub-millimetre Array (ALMA) to image the embedded clusters NGC6334-I and NGC6334-I(N) in the continuum emission at 87.6GHz. We achieved a spatial resolution of 1300au, enough to resolve different compact cores and fragments, and to study the properties of the clusters. We detected 142 compact sources distributed over the whole surveyed area. The ALMA compact sources are clustered in different regions. We used different machine-learning algorithms to identify four main clusters: NGC6334-I, NGC6334-I(N), NGC6334-I(NW), and NGC6334-E. The typical separations between cluster members range from 4000au to 12000au. These separations, together with the core masses (0.1-100M_{sun}_), are in agreement with the fragmentation being controlled by turbulence at scales of 0.1pc. We find that the CMFs show an apparent excess of high-mass cores compared to the stellar Initial Mass Function. We evaluated the effects of temperature and unresolved multiplicity on the derived slope of the CMF. Based on this, we conclude that the excess of high-mass cores might be spurious and due to inaccurate temperature determinations and/or resolution limitations. We searched for evidence of mass segregation in the clusters and we find that clusters NGC6334-I and NGC6334-I(N) show hints of segregation with the most massive cores located in the centre of the clusters. We searched for correlations between the physical properties of the four embedded clusters and their evolutionary stage (based on the presence of Hii regions and infrared sources). NGC6334-E appears as the most evolved cluster, already harboring a well-developed Hii region. NGC6334-I is the second-most evolved cluster with an ultra-compact Hii region. NGC6334-I(N) contains the largest population of dust cores distributed in two filamentary structures and no dominant Hii region. Finally, NGC6334-I(NW) is a cluster of mainly low-mass dust cores with no clear signs of massive cores or Hii regions.We find a larger separation between cluster members in the more evolved clusters favoring the role of gas expulsion and stellar ejection with evolution. The mass segregation, seen in the NGC6334-I and NGC6334-I(N) clusters, suggests a primordial origin for NGC6334-I(N). In contrast, the segregation in NGC6334-I might be due to dynamical effects. Finally, the lack of massive cores in the most evolved cluster suggests that the gas reservoir is already exhausted, while the less evolved clusters still have a large gas reservoir along with the presence of massive cores. In general, the fragmentation process of NGC6334 at large scales (from filament to clump, i.e. at about 1pc) is likely governed by turbulent pressure, while at smaller scales (scale of cores and sub-fragments, i.e. a few hundred au) thermal pressure starts to be more significant.

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