- ID:
- ivo://CDS.VizieR/J/A+A/544/L7
- Title:
- IRAS 16293-2422 ALMA maps
- Short Name:
- J/A+A/544/L7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We focus on the kinematical properties of a proto-binary to study the infall and rotation of gas toward its two protostellar components. We present ALMA Science Verification observations with high-spectral resolution of IRAS 16293-2422 at 220.2GHz. The wealth of molecular lines in this source and the very high spectral resolution offered by ALMA allow us to study the gas kinematics with unprecedented detail.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/299/347
- Title:
- IRAS galaxies behind Taurus clouds
- Short Name:
- J/A+A/299/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a complete search for IRAS galaxies in the Taurus molecular cloud region at l=169deg to 177deg and b=-19deg to -12deg. We selected a total number of 36 galaxies and galaxy candidates and looked for the 21-cm H I line in 25 objects; we detected H I emission in five of them including one with previously unknown redshift. The spatial density of IRAS galaxies with cz=4000 to 6000km/s is lower in this region than in the adjacent regions at both sides along galactic longitude, where the Perseus supercluster and the Gemini-Monoceros filament are respectively located.
- ID:
- ivo://CDS.VizieR/J/other/BSAO/50.115
- Title:
- IRAS-TEXAS cross-identifications
- Short Name:
- J/other/BSAO/50.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A procedure of sampling objects by way of cross-identification of the low-frequency radio catalogue of objects obtained with the aid of the Texas interferometer at the frequency 365MHz and of the IRAS (Cat. <II/125>) catalogue is discussed. Statistical properties of different subsamples of sources are investigated. From the results of cross-identification with the radio catalogues of the database CATS (Verkhodanov et al., 1997BaltA...6..275V), continuous radio spectra of objects are plotted, identification with optical and X-ray catalogues is carried out. From the steep spectrum objects sources are selected for further studies.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A87
- Title:
- IRAS17020+4544 VLBA 5, 8, 15, 24GHz images
- Short Name:
- J/A+A/600/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent XMM-Newton observations have revealed that IRAS 17020+4544 is a very unusual example of black hole windproduced feedback by a moderately luminous AGN in a spiral galaxy. Since the source is known for being a radio emitter, we investigated about the presence and the properties of a non-thermal component. We observed IRAS 17020+4544 with the Very Long Baseline Array at 5, 8, 15, and 24GHz within a month of the 2014 XMM-Newton observations. We further analysed archival data taken in 2000 and 2012. Results. We detect the source at 5GHz and on short baselines at 8GHz. At 15 and 24 GHz, the source is below our baseline sensitivity for fringe fitting, indicating the lack of prominent compact features. The morphology is that of an asymmetric double, with significant diffuse emission. The spectrum between 5 and 8GHz is rather steep (S{nu}~nu^-(1.0+/-0.2)^). Our re-analysis of the archival data at 5 and 8GHz provides results consistent with the new observations, suggesting that flux density and structural variability are not important in this source. We put a limit on the separation speed between the main components of <0.06c. IRAS 17020+4544 shows interesting features of several classes of objects: its properties are typical of compact steep spectrum sources, low power compact sources, radio-emitting narrow line Seyfert 1 galaxies. However, it can not be classified in any of these categories, remaining so far a one-of-a-kind object.
- ID:
- ivo://CDS.VizieR/J/MNRAS/302/222
- Title:
- ISO ELAIS 20cm VLA survey regions
- Short Name:
- J/MNRAS/302/222
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Very Large Array (VLA) in C configuration to carry out a sensitive 20-cm radio survey of regions of the sky that have been surveyed in the far-infrared (FIR) over the wavelength range 5-200{mu}m with ISO (Infrared Space Observatory) as part of the European Large-Area ISO Survey (ELAIS). As usual in surveys based on a relatively small number of overlapping VLA pointings, the flux limit varies over the area surveyed: from a 5{sigma} limit of 0.135mJy over an area of 0.12deg^2^ to 1.15mJy or better over the whole region covered of 4.22deg^2^. In this paper we present the complete radio catalogue of 867 sources, 428 of which form a complete sample in the flux range 0.2-1.0mJy. These regions of the sky have previously been surveyed to shallower flux limits at 20cm with the VLA as part of the VLA D configuration NVSS (full width at half-maximum, FWHM=45arcsec) and VLA B configuration FIRST (FWHM=5arcsec) surveys. Our whole survey has a nominal 5{sigma} flux limit a factor of 2 below that of the NVSS; 3.4deg^2^ of the survey reaches the nominal flux limit of the FIRST survey and 1.5deg^2^ reaches 0.25mJy, a factor of 4 below the nominal FIRST survey limit. In addition, our survey is at a resolution intermediate between the two surveys and thus is well suited for a comparison of the reliability and resolution-dependent surface brightness effects that affect interferometric radio surveys. We have carried out a detailed comparison of our own survey and these two independent surveys in order to assess the reliability and completeness of each. Considering the whole sample, we found that to the 5{sigma} nominal limits of 2.3 and 1.0mJy, respectively, the NVSS and FIRST surveys have a completeness of 96^+2^_-3_ and 89^+2^_-3_ per cent and a reliability of 99^+1^_-2_ and 94^+2^_-2_ per cent.
- ID:
- ivo://CDS.VizieR/J/MNRAS/305/297
- Title:
- ISO ELAIS 1.4GHz survey
- Short Name:
- J/MNRAS/305/297
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A deep survey of the European Large-Area ISO Survey (ELAIS) field in the southern celestial hemisphere (hereinafter S1) has been carried out with the Australia Telescope Compact Array (ATCA) at 1.4GHz. The S1 region, covering about 4deg^2^, has also been surveyed in the mid- and far-infrared (5-200mm) with the Infrared Space Observatory (ISO). The radio survey provides uniform coverage of the entire S1 region, with a sensitivity (5{sigma}) of 0.4mJy over the whole area and 0.2mJy in the centre. To this sensitivity, virtually all the radio counterparts of the far-infrared extragalactic ISO sources should be detected. This paper presents a radio sample -- complete at the 5{sigma} level -- consisting of 581 sources detected at 1.4GHz. Of these radio sources, 349 have peak flux density in the range 0.2-1mJy, forming a new homogeneous sample of sub-mJy radio sources. Due to its size, depth and multiwaveband coverage, the sample will allow us to study in greater detail the sub-mJy radio source population.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/492
- Title:
- JCMT/SCUBA2 objects in COSMOS and UDS fields
- Short Name:
- J/MNRAS/469/492
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present physical properties [redshifts (z), star-formation rates (SFRs) and stellar masses (M*)] of bright (S_850_>=4mJy) submm galaxies in the ~=2deg^2^ COSMOS and UDS fields selected with SCUBA-2/JCMT. We complete the galaxy identification process for all (~=2000) S/N>=3.5 850-{mu}m sources, but focus our scientific analysis on a high-quality subsample of 651 S/N>=4 sources with complete multiwavelength coverage including 1.1-mm imaging. We check the reliability of our identifications, and the robustness of the SCUBA-2 fluxes by revisiting the recent ALMA follow-up of 29 sources in our sample. Considering >4mJy ALMA sources, our identification method has a completeness of ~=86 per cent with a reliability of ~=92 per cent, and only ~=15-20 per cent of sources are significantly affected by multiplicity (when a secondary component contributes >1/3 of the primary source flux). The impact of source blending on the 850-{mu}m source counts as determined with SCUBA-2 is modest; scaling the single-dish fluxes by ~=0.9 reproduces the ALMA source counts. For our final SCUBA-2 sample, we find median z=2.40^+0.10^_-0.04_, SFR=287+/-6M_{sun}_/yr and log(M*/M_{sun)_=11.12+/-0.02 (the latter for 349/651 sources with optical identifications). These properties clearly locate bright submm galaxies on the high-mass end of the 'main sequence' of star-forming galaxies out to z~= 6, suggesting that major mergers are not a dominant driver of the high-redshift submm-selected population. Their number densities are also consistent with the evolving galaxy stellar mass function. Hence, the submm galaxy population is as expected, albeit reproducing the evolution of the main sequence of star-forming galaxies remains a challenge for theoretical models/simulations.
- ID:
- ivo://CDS.VizieR/J/A+A/647/A67
- Title:
- Jet collimation in NGC 315
- Short Name:
- J/A+A/647/A67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The collimation of relativistic jets in galaxies is a poorly understood process. Detailed radio studies of the jet collimation region have been performed so far in a few individual objects, providing important constraints for jet formation models. However, the extent of the collimation zone as well as the nature of the external medium possibly confining the jet are still debated. In this article, we present a multifrequency and multiscale analysis of the radio galaxy NGC 315, including the use of mm-VLBI data up to 86GHz, aimed at revealing the evolution of the jet collimation profile. We then consider results from the literature to compare the jet expansion profile in a sample of 27 low-redshift sources, mainly comprising radio galaxies and BL Lacs, which were classified based on the accretion properties as low-excitation (LEG) and high-excitation (HEG) galaxies. We propose that the jet collimation in NGC 315 is completed on sub-parsec scales. A transition from a parabolic to conical jet shape is detected at z_t_=0.58+/-0.28-parsecs or ~5x10^3& Schwarzschild radii (Rs) from the central engine, a distance which is much smaller than the Bondi radius, rB~92pc, estimated based on X-ray data. The jet in this and in a few other LEG in our sample may be initially confined by a thick disk extending out to ~10^3^-10^4^R_{sun}_. A comparison between the mass-scaled jet expansion profiles of all sources indicates that jets in HEG are surrounded by thicker disk-launched sheaths and collimate on larger scales with respect to jets in LEG. These results suggest that disk winds play an important role in the jet collimation mechanism, particularly in high-luminosity sources. The impact of winds on the origin of the FRI and FRII dichotomy in radio galaxies is also discussed.
- ID:
- ivo://CDS.VizieR/J/ApJ/861/97
- Title:
- Jet power of blazars from the TGSS at 150MHz
- Short Name:
- J/ApJ/861/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The composition and energy dissipation in jets are two of the fundamental questions of jet physics that are not fully understood. In this paper, we attempt to constrain the composition, magnetization, and radiative efficiency for blazars with the recently released low-frequency radio catalog of the TIFR GMRT Sky Survey at 150MHz. The jet power estimated from the low-frequency radio emission is much lower than that derived from spectral energy distribution fitting assuming one proton per electron. Assuming the jet power estimated from low-frequency radio emission is physical, the fraction of electron/positron pairs can be constrained with n_pairs_/n_p_~10. By comparing the power carried by the magnetic field and radiation with the jet power estimated from the low-frequency radio emission, we find both the relatively high magnetization parameter of {sigma}~0.5 and the radiative efficiency of {eta}~0.4 in the dissipation region of blazars. These results suggest that magnetic reconnection processes may play an important role in the energy dissipation of blazars. We also explore the connection between these three parameters (n_pairs_/n_p_, {sigma}, and {eta}) and the black hole mass, disk luminosity, and Eddington ratio. No significant correlation is found, except that {sigma} shows a possible correlation with disk luminosity.
- ID:
- ivo://CDS.VizieR/J/ApJ/602/850
- Title:
- JHK' photometry near IRAS 18507+0121
- Short Name:
- J/ApJ/602/850
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed the massive star-forming region IRAS 18507+0121 at millimeter wavelengths in 3mm continuum emission, H^13^CO+ (J=1-0) and SiO (v=0,J=2-1) line emission, and at near-infrared (NIR) wavelengths between 1.2 and 2.1{mu}m. Two compact molecular cores are detected: one north and one south, separated by ~40". The northern molecular core contains a newly discovered, deeply embedded, B2 protostar surrounded by several hundred solar masses of warm gas and dust, G34.4+0.23 MM. Based on the presence of warm dust emission and the lack of detection at NIR wavelengths, we suggest that G34.4+0.23 MM may represent the relatively rare discovery of a massive protostar (e.g., analogous to a low-mass "Class 0" protostar). The southern molecular core is associated with an NIR cluster of young stars and an ultracompact HII region, G34.4+0.23, with a central B0.5 star. The fraction of NIR stars with excess infrared emission indicative of circumstellar material is greater than 50%, which suggests an upper limit on the age of the IRAS 18507+0121 star-forming region of 3Myr.
