- ID:
- ivo://CDS.VizieR/J/ApJS/151/271
- Title:
- Millennium Arecibo 21-cm Survey. III.
- Short Name:
- J/ApJS/151/271
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We outline the theory and practice of measuring the four Stokes parameters of spectral lines in emission/absorption observations. We apply these concepts to our Arecibo H I absorption line data and present the results. We include a detailed discussion of instrumental effects arising from polarized beam structure and its interaction with the spatially extended emission line structure. At Arecibo, linear polarization [Stokes (Q,U)] has much larger instrumental effects than circular (Stokes V). We show how to reduce the instrumental contributions to V and to evaluate upper limits to its remaining instrumental errors by using the (Q,U) results. These efforts work well for opacity spectra but not for emission spectra. Arecibo's large central blockage exacerbates these effects, particularly for emission profiles, and other telescopes with weaker sidelobes are not as susceptible. We present graphical results for 41 sources; we analyze these absorption spectra in terms of Gaussian components, which number 136, and present physical parameters including magnetic field for each.
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- ID:
- ivo://CDS.VizieR/J/A+A/476/1243
- Title:
- Millimeter continuum mapping of Cygnus X
- Short Name:
- J/A+A/476/1243
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a millimeter continuum survey of the entire Cygnus X molecular complex. We used the MAMBO and MAMBO-2 bolometer arrays on the IRAM 30m telescope to map a 3deg^2^ area at 1.2mm (see fits files of Figures 2, kept to 11" resolution). Our MAMBO-2 imaging gives a complete view of the cloud structures ranging from 0.03pc to 5pc, i.e. from dense cores to clumps. We perform a multi-resolution analysis to extract 129 compact dense cores (~0.1pc, see Table 1) and identify 40 massive large-scale clumps (~0.7pc, see Table 2). The 21um fluxes arising from dense cores are taken from the MSX point source catalog (MSX C6, Cat. <V/114>).
- ID:
- ivo://CDS.VizieR/J/A+A/602/A37
- Title:
- Millimeter RRL in ATLASGAL-selected massive clumps
- Short Name:
- J/A+A/602/A37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of millimeter wavelength radio recombination lines (mm-RRLs) are used to search for HII regions in an unbiased way that is complementary to many of the more traditional methods previously used (e.g., radio continuum, far-infrared colors, maser emission). The mm-RRLs can be used to derive physical properties of HII regions and to provide velocity information of ionized gas. We carried out targeted mm-RRL observations (39<= principal quantum number (n) <=65 and {Delta}n = 1, 2, 3, and 4, named Hn{alpha}, Hn{beta}, Hn{gamma}, and Hn{delta}) using the IRAM 30m and Mopra 22m telescopes. In total, we observed 976 compact dust clumps selected from a catalog of ~10000 sources identified by the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL). The sample was selected to ensure a representative mix of star-forming and quiescent clumps such that a variety of different evolutionary stages is represented. Approximately half of the clumps are mid-infrared quiet while the other half are mid-infrared bright. We detected Hn{alpha} mm-RRL emission toward 178 clumps; Hn{beta}, Hn{gamma}, and Hn{delta} were also detected toward 65, 23, and 22 clumps, respectively. This is the largest sample of mm-RRLs detections published to date. Comparing the positions of these clumps with radio continuum surveys we identified compact radio counterparts for 134 clumps, confirming their association with known HII regions. The nature of the other 44 detections is unclear, but 8 detections are thought to be potentially new HII regions while the mm-RRL emission from the others may be due to contamination from nearby evolved HII regions. Broad linewidths are seen toward nine clumps (linewidth>40km/s) revealing significant turbulent motions within the ionized gas; in the past, such wide linewidths were found toward very compact and dense HII regions. We find that the systemic velocity of the associated dense molecular gas, traced by H^13^CO^+^(1-0), is consistent with the mm-RRL velocities and confirms them as embedded HII regions. We also find that the linewidth of the H^13^CO^+^(1-0) emission is significantly wider than those without mm-RRL detection, indicating a physical connection between the embedded H II region and their natal environments. We also find a correlation between the integrated fluxes of the mm-RRLs and the 6cm continuum flux densities of their radio counterparts (the correlation coefficient, {rho}, is 0.70). By calculating the electron densities we find that the mm-RRL emission is associated with HII regions with n_e_<10^5^cm^3^ and HII region diameter >0.03pc. We detected mm-RRLs toward 178 clumps and identified eight new HII region candidates. The broad mm-RRL from nine clumps may indicate that they arise in very young hyper-compact HII regions. The mm-RRLs trace the radio continuum sources detected by high-resolution observations and their line parameters show associations with the embedded radio sources and their parental molecular clumps.
- ID:
- ivo://CDS.VizieR/J/A+A/390/501
- Title:
- Millimetre observations of carbon stars. I.
- Short Name:
- J/A+A/390/501
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Millimetre observations of IRAS selected red carbon stars are presented. About 260 stars have been observed with SEST and IRAM in the CO (1-0) and CO (2-1) lines and partially in HCN (1-0) and SiO (3-2). An overall detection rate, in at least one line, of about 80% is achieved. The survey represents the second largest survey for AGB stars, and the largest ever for carbon stars. Two new detections in SiO (3-2) in carbon stars are reported. When available, the SiO/HCN and HCN/CO(1-0) line ratios are consistent with the ratios expected for carbon stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/723/1110
- Title:
- MIPS 24um observations of the HDFS
- Short Name:
- J/ApJ/723/1110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present MIPS 24um observations of the Hubble Deep Field South taken with the Spitzer Space Telescope. The resulting image is 254arcmin^2^ in size and has a sensitivity ranging between ~12 and ~30uJy rms, with a median sensitivity of ~20uJy rms. A total of 495 sources have been catalogued with a signal-to-noise ratio greater than 5{sigma}. The source catalog is presented as well as source counts which have been corrected for completeness and flux boosting. The IR sources are then combined with MUSYC optical/NIR and ATHDFS radio observations to obtain redshifts and radio flux densities of the sample. We use the IR/radio flux density ratio (q_24_) to explore the IR-radio correlation for this IR sample and find q_24_=0.71+/-0.31 for sources detected in both IR and radio. The results are extended by stacking IR sources not detected in the radio observations and we derive an average q_24_ for redshift bins between 0<z<2.5. We find that the high-redshift (z>1) sources have an average q_24_ ratio which is better fit by local LIRG SEDs rather than local ULIRG SEDs, indicating that high-redshift ULIRGs differ in their IR/radio properties. So, ULIRGs at high-redshift have SEDs different from those found locally. Infrared-faint radio sources are examined, and while nine radio sources do not have an MIPS detection and are therefore radio-loud active galactic nuclei (AGNs), only one radio source has an extreme IRAC 3.6um to radio flux density ratio indicating it is a radio-loud AGN at z>1.
1016. Miyun 232MHz survey
- ID:
- ivo://CDS.VizieR/VIII/44
- Title:
- Miyun 232MHz survey
- Short Name:
- VIII/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A meter-wave survey of the sky region north of declination +30{deg} has been carried out with the Miyun Synthesis Radio Telescope (MSRT), Beijing Astronomical Observatory, at 232MHz. It is a moderately deep survey. The observations were made between January 1985 and December 1993. The covered sky area is divided into 156 fields of view. Basically all adjacent fields are separated by 8 degree angular distance. Fields #54, #56, #115, #116, have no data yet. A catalog of 34462 radio sources is given in Table 2. Table3 shows the information on the 152 fields of view.
- ID:
- ivo://CDS.VizieR/J/other/AcApS/16.103
- Title:
- Miyun 232MHz survey: reliability study
- Short Name:
- J/other/AcApS/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A meter-wave sky survey of the region north of declination +30deg has been carried out with the Miyun Synthesis Radio Telescope (MSRT) at 232MHz. The Miyun general catalogue (MGC) contains 26957 radio sources except those located in the galactic plane, its electronic version is available now. Completeness and uniformity of the MGC has been discussed recently (Peng et al, 1995AcApS..15..383P). In this paper, we provide evidence of reliability of the MGC by comparing the MSRT data with other published radio catalogues and also by analyzing the reason why part of the detected sources in the MGC could not be recorded by previous surveys.
- ID:
- ivo://CDS.VizieR/J/ApJS/103/331
- Title:
- mJy radio sources at 1.4 GHz
- Short Name:
- J/ApJS/103/331
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From the 1.4GHz radio survey of Condon, Dickey, & Salpeter (Cat. <J/AJ/99/1071>) in a region much devoid of rich galaxy clusters at redshifts z<0.43 we selected a "distant" sample of 57 radio sources complete to a 1.4GHz flux density of 35mJy and a "nearby" sample of 36 mostly weaker radio sources which are optically brighter than B~19mag. Our ultimate goals are (1) to study the radio, optical, and near-IR properties of those high-redshift (z~1), moderate-power radio sources in the distant sample and to compare them with that of more powerful radio sources, and (2) to make a comparison of primarily noncluster radio sources in the nearby sample with a companion survey of radio sources in a pair of rich superclusters at z~0.1. In this first paper of a series, we report our new C-array VLA continuum snapshots at 4.86GHz and optical R-band CCD imaging photometry for these two samples and tabulate the observational results on individual sources. Some direct sample statistical properties are also discussed in the paper and summarized as follows: (1) The distant sample: (a) The sample median flux density at 1.4GHz is about 65mJy. (b) The majority (80%) of the sample sources have a steep spectrum between 1.4 and 4.86GHz with a spectral index around 0.9. Nineteen (90%) of the 21 sources that are fully resolved at 4.86 GHz (i.e., angular sizes {theta}>11") have a radio morphology of Fanaroff-Riley (FR) II type. (c) Thirty-seven (88%) of the 42 optically imaged sample sources were optically identified to a limiting R-band magnitude of R~23.5mag. About 15% of the identified radio sources appear to be point sources, and the others are extended galaxies with an appearance similar to nearby elliptical galaxies. (d) Twenty-eight (76%) of the optically identified sources have R>20mag, suggesting that these are probably distant (z>0.8), with a redshift distribution peaking at z~1, where their radio luminosities are about 10 times the break power between the FR I and II classes. (e) We found no strong evidence for the radio and optical axes of the resolved radio sources (i.e., {theta}>5") to be correlated or anticorrelated, nor any evidence for strong clustering around sample radio sources on average. (2) The nearby sample: except for R<15, the sample is dominated by elliptical galaxies with 16<R<18.5mag and a spectral index distribution similar to that of the distant sample. Based on the radial distribution of optical objects around each radio source, we found that the average radio source environment becomes richer from that characteristic of galaxy groups for R<17mag (z<0.2) to that of galaxy groups to clusters at R>18mag (z>0.3) .
- ID:
- ivo://CDS.VizieR/J/A+A/585/A21
- Title:
- M83 magnetic and gaseous spiral arms images
- Short Name:
- J/A+A/585/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The magnetic field configurations in several nearby spiral galaxies contain magnetic arms that are sometimes located between the material arms. The nearby barred galaxy M83 provides an outstanding example of a spiral pattern seen in tracers of gas and magnetic field. We analyse the spatial distribution of magnetic fields in M83 and their relation to the material spiral arms. Isotropic and anisotropic wavelet transforms are used to decompose the images of M83 in various tracers to quantify structures in a range of scales from 0.2 to 10kpc. We used radio polarization observations at {lambda}6.2cm and {lambda}13cm obtained with the VLA, Effelsberg and ATCA telescopes and APEX sub-mm observations at 870{mu}m, which are first published here, together with maps of the emission of warm dust, ionized gas, molecular gas, and atomic gas. The spatial power spectra are similar for the tracers of dust, gas, and total magnetic field, while the spectra of the ordered magnetic field are significantly different. As a consequence, the wavelet cross-correlation between all material tracers and total magnetic field is high, while the structures of the ordered magnetic field are poorly correlated with those of other tracers. The magnetic field configuration in M83 contains pronounced magnetic arms. Some of them are displaced from the corresponding material arms, while others overlap with the material arms. The pitch angles of the magnetic and material spiral structures are generally similar. The magnetic field vectors at {lambda}6.2cm are aligned with the outer material arms, while significant deviations occur in the inner arms and, in particular, in the bar region, possibly due to non-axisymmetric gas flows. Outside the bar region, the typical pitch angles of the material and magnetic spiral arms are very close to each other at about 10{deg}. The typical pitch angle of the magnetic field vectors is about 20{deg} larger than that of the material spiral arms. One of the main magnetic arms in M83 is displaced from the gaseous arms similarly to the galaxy NGC6946, while the other main arm overlaps a gaseous arm, similar to what is observed in M51. We propose that a regular spiral magnetic field generated by a mean-field dynamo is compressed in material arms and partly aligned with them. The interaction of galactic dynamo action with a transient spiral pattern is a promising mechanism for producing such complicated spiral patterns as in M83.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A50
- Title:
- 1.3mm and 3mm emission maps or 4 Ae/Be stars
- Short Name:
- J/A+A/531/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Herbig Ae stars (HAe) are the precursors of Vega-type systems and, therefore, crucial objects in planet formation studies. Thus far, only a few disks associated with HAe stars have been studied using millimetre interferometers. Our aim is to determine the dust evolution and the lifetime of the disks associated with Herbig Ae stars. We imaged the continuum emission at ~3mm and ~1.3mm of the Herbig Ae/Be stars BD+61154, RR Tau, VY Mon and LkH{alpha} 198 using the Plateau de Bure Interferometer (PdBI). These stars are in the upper end of the stellar mass range of the Herbig Ae stars (M_*_>3M_{sun}_). Our measurements were used to complete the Spectral Energy Distribution (SED). The modelling of the SED, in particular the FIR-mm part, allow us to determine the masses and dust properties of these disks. We detected the disks associated with BD+61154, RR Tau and VY Mon with disk masses of 0.35M_{sun}_, 0.05M_{sun}_ and 0.40M_{sun}_ respectively. The disk around LkH{alpha} 198 was not detected with an upper limit to the disk mass of 0.004M_{sun}_. We detected, however, the disks associated with the younger stellar objects LkH{alpha} 198--IR and LkH{alpha} 198--mm that are located in the vicinity of LkH{alpha} 198. The fitting of the mm part of the SED reveal that the grains in the mid-plane of the disks around BD+61154, RR Tau and VY Mon have sizes of ~1-1000um. Therefore, grains have not grown to centimetre sizes in these disks yet. These massive (M_*_>3M_{sun}_) and young (~1Myr) HAe stars are surrounded by massive (>~0.04M_{sun}_) disks with grains of micron-millimetre sizes. Although grain growth is proceeding in these disks, their evolutionary stage is prior to the formation of planetesimals. These disks are less evolved than those detected around T Tauri and Herbig Be stars.