- ID:
- ivo://CDS.VizieR/J/A+A/564/A128
- Title:
- Continuum and CO maps of 3C 293
- Short Name:
- J/A+A/564/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Powerful radio galaxies show evidence of ongoing active galactic nuclei (AGN) feedback, mainly in the form of fast, massive outflows. But it is not clear how these outflows affect the star formation of their hosts. We investigate the different manifestations of AGN feedback in the evolved, powerful radio source 3C 293 and their impact on the molecular gas of its host galaxy, which harbors young star-forming regions and fast outflows of H i and ionized gas. We study the distribution and kinematics of the molecular gas of 3C 293 using high spatial resolution observations of the ^12^CO(1-0) and ^12^CO(2-1) lines, and the 3mm and 1 continuum taken with the IRAM Plateau de Bure interferometer. We mapped the molecular gas of 3C 293 and compared it with the dust and star-formation images of the host. We searched for signatures of outflow motions in the CO kinematics, and re-examined the evidence of outflowing gas in the HI spectra. We also derived the star formation rate (SFR) and star formation efficiency (SFE) of the host with all available SFR tracers from the literature, and compared them with the SFE of young and evolved radio galaxies and normal star-forming galaxies. The ^12^CO(1-0) emission line shows that the molecular gas in 3C 293 is distributed along a massive (M(H_2_)~2.2x10^10^M_{sun}_) ~24" (21kpc) diameter warped disk, that rotates around the AGN. Our data show that the dust and the star formation are clearly associated with the CO disk. The ^12^CO(2-1) emission is located in the inner 7kpc (diameter) region around the AGN, coincident with the inner part of the ^12^CO(1-0) disk. Both the ^12^CO(1-0) and ^12^CO(2-1) spectra reveal the presence of an absorber against the central regions of 3C 293 that is associated with the disk. We do not detect any fast (500km/s) outflow motions in the cold molecular gas. The host of 3C 293 shows an SFE consistent with the Kennicutt-Schmidt law of normal galaxies and young radio galaxies, and it is 10-50 times higher than the SFE estimated with the 7.7um PAH emission of evolved radio galaxies. Our results suggest that the apparently low SFE of evolved radio galaxies may be caused by an underestimation of the SFR and/or an overestimation of the molecular gas densities in these sources. The molecular gas of 3C 293, while not incompatible with a mild AGN-triggered flow, does not reach the high velocities (500km/s) observed in the HI spectrum. We find no signatures of AGN feedback in the molecular gas of 3C 293.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/866/133
- Title:
- Continuum-H{beta} light curves of 5 Seyfert 1
- Short Name:
- J/ApJ/866/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from a reverberation-mapping campaign undertaken during the first half of 2012, with additional data on one active galactic nucleus (AGN) (NGC 3227) from a 2014 campaign. Our main goals are (1) to determine the black hole masses from continuum-H{beta} reverberation signatures, and (2) to look for velocity-dependent time delays that might be indicators of the gross kinematics of the broad-line region. We successfully measure H{beta} time delays and black hole masses for five AGNs, four of which have previous reverberation mass measurements. The values measured here are in agreement with earlier estimates, though there is some intrinsic scatter beyond the formal measurement errors. We observe velocity-dependent H{beta} lags in each case, and find that the patterns have changed in the intervening five years for three AGNs that were also observed in 2007.
- ID:
- ivo://CDS.VizieR/J/A+A/411/381
- Title:
- CO observation of isolated galaxies
- Short Name:
- J/A+A/411/381
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ^12^CO(J=1-0) line observations of 99 galaxies obtained with the SEST 15m, the Kitt Peak 12m and the IRAM 30m telescopes. The target galaxies were selected from the catalogue of isolated galaxies of Karachentseva (1973, Cat. <VII/82>). These data are thus representative of the CO properties of isolated late-type galaxies. All objects were observed in their central position, those with large angular sizes were mapped. These new measurements are used to estimate the molecular gas mass of the target galaxies. The molecular gas is on average ~18% of the atomic gas mass.
- ID:
- ivo://CDS.VizieR/J/ApJ/761/37
- Title:
- CO observations in giant molecular clouds of M33
- Short Name:
- J/ApJ/761/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a giant molecular cloud (GMC) catalog of M33 (NGC598), containing 71 GMCs in total, based on wide-field and high-sensitivity CO(J=3-2) observations with a spatial resolution of 100pc using the ASTE 10m telescope. Employing archival optical data, we identify 75 young stellar groups (YSGs) from the excess of the surface stellar density, and estimate their ages by comparing with stellar evolution models. A spatial comparison among the GMCs, YSGs, and H II regions enable us to classify GMCs into four categories: Type A, showing no sign of massive star formation (SF); Type B, being associated only with H II regions; Type C, with both H II regions and <10Myr old YSGs; and Type D, with both H II regions and 10-30Myr YSGs. Out of 65 GMCs (discarding those at the edges of the observed fields), 1 (1%), 13 (20%), 29 (45%), and 22 (34%) are Types A, B, C, and D, respectively. We interpret these categories as stages in a GMC evolutionary sequence. Assuming that the timescale for each evolutionary stage is proportional to the number of GMCs, the lifetime of a GMC with a mass >10^5^M_{sun}_ is estimated to be 20-40Myr. In addition, we find that the dense gas fraction as traced by the CO(J=3-2)/CO(J=1-0) ratio is enhanced around SF regions. This confirms a scenario where dense gas is preferentially formed around previously generated stars, and will be the fuel for the next stellar generation. In this way, massive SF gradually propagates in a GMC until gas is exhausted.
- ID:
- ivo://CDS.VizieR/J/A+A/295/585
- Title:
- CO observations in NGC 1365
- Short Name:
- J/A+A/295/585
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of the J=1-0 and J=2-1 CO observations are presented
- ID:
- ivo://CDS.VizieR/J/A+AS/118/47
- Title:
- CO observations in spirals
- Short Name:
- J/A+AS/118/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 1300{mu}m continuum observations and measurements of the CO (1-0) and (2-1) emission from the inner regions of 98 normal galaxies. The spatial resolution ranges from 11arcsec to 45arcsec. The sources come from a complete FIR selected sample of 138 inactive spirals with an optical diameter D_25_<=180arcsec.
- ID:
- ivo://CDS.VizieR/VII/64
- Title:
- CO Observations of Galaxies
- Short Name:
- VII/64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a complete summary of all observations of CO isotopes in galaxies up to spring 1984. It consists of seven tables. Refs.dat describes the reference for CO observations of galaxies. Telescop.dat describes the properties of the telescopes used for observations. Detect.dat and uprlmits.dat contain a compilation of data on galaxies that have been observed in CO. Most of the characteristics listed here are observed properties. The detected galaxies are listed first, followed by galaxies with upper limits. Upper limits are given for detected galaxies if the detection is disputed or if the limits refer to transitions or regions that have not yet been detected. Temp.dat is a comparison of the antenna temperature scales used in the references in this catalog. Maps.dat lists the coverage, resolution, observed structure of CO maps of galaxies, and notes.dat contains notes to tables.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A107
- Title:
- CO observations of major merger pairs at z=0
- Short Name:
- J/A+A/627/A107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CO observations of 78 spiral galaxies in local merger pairs. These galaxies represent a subsample of a Ks-band-selected sample consisting of 88 close major-merger pairs (HKPAIRs), 44 spiral-spiral (S+S) pairs, and 44 spiral-elliptical (S+E) pairs, with separation <20h^-1^kpc and mass ratio <2.5. For all objects, the star formation rate (SFR) and dust mass were derived from Herschel PACS and SPIRE data, and the atomic gas mass, MHI, from the Green Bank Telescope HI observations. The complete data set allows us to study the relation between gas (atomic and molecular) mass, dust mass, and SFR in merger galaxies. We derive the molecular gas fraction (M_H2_/M*), molecular-to-atomic gas mass ratio (M_H2_/M_HI_), gas-to-dust mass ratio and SFE (=SFR/M_H2_) and study their dependences on pair type (S+S compared to S+E), stellar mass, and the presence of morphological interaction signs. We find an overall moderate enhancement (~2x) in both molecular gas fraction (M_H2_/M*) and molecular-to-atomic gas ratio (M_H2_/M_HI_) for star-forming galaxies in major-merger pairs compared to non-interacting comparison samples, whereas no enhancement was found for the SFE nor for the total gas mass fraction ((MHI+MH2)/M^Cstar). When divided into S+S and S+E, low mass and high mass, and with and without interaction signs, there is a small difference in SFE, a moderate difference in M_H2_/M*, and a strong difference in M_H2_/M_HI_ between subsamples. For the molecular-to-atomic gas ratio M_H2_/M_HI_, the difference between S+S and S+E subsamples is 0.55+/-0.18dex and between pairs with and without interaction signs is 0.65+/-0.16dex. Together, our results suggest that (1) star formation enhancement in close major-merger pairs occurs mainly in S+S pairs after the first close encounter (indicated by interaction signs)^Mbecause the HI gas is compressed into star-forming molecular gas by the tidal torque; and (2) this effect is much weakened in the S+E pairs.
- ID:
- ivo://CDS.VizieR/J/A+A/554/A11
- Title:
- CO observations of polar ring galaxies
- Short Name:
- J/A+A/554/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have searched for CO lines in a sample of 21 new morphologically determined polar ring galaxies (of which 9 are kinematically confirmed), obtained from a wide search in the Galaxy Zoo project by Moiseev and collaborators. Polar ring galaxies (PRG) are a unique class of objects, tracing special episodes in the galaxy mass assembly: they could be formed through galaxy interaction, merging, but also through accretion from cosmic filaments. Beside, they enable the study of dark matter haloes in 3 dimensions. The polar ring itself is a sub-system rich in gas, where molecular gas is expected, and new stars are formed. Among the sample of 21 PRG, we have detected five CO-rich systems, that can now be followed up with higher spatial resolution. Their average molecular mass is 9.4x10^9^M_{sun}_, and their average gas fraction is 27% of their baryonic mass, with a range from 15 to 43%, implying that they just accreted a large amount of gas. The position of the detected objects in the velocity- magnitude diagram is offset from the Tully-Fisher relation of normal spirals, as was already found for PRG. This work is part of our multi-wavelength project to determine the detailed morphology and dynamics of Polar-Ring galaxies, test through numerical models their formation scenario, and deduce their dark matter content and 3D-shape.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A24
- Title:
- Cool carbon stars in the halo and Fornax dSph
- Short Name:
- J/A+A/562/A24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The population of cool carbon (C) stars located far from the galactic plane is probably made of debris of small galaxies such as the Sagittarius dwarf spheroidal galaxy (Sgr), which are disrupted by the gravitational field of the Galaxy. We aim to know this population better through spectroscopy, 2MASS photometric colours, and variability data. When possible, we compared the halo results to C star populations in the Fornax dwarf spheroidal galaxy, Sgr, and the solar neighbourhood. We first present a few new discoveries of C stars in the halo and in Fornax. The number of spectra of halo C stars is now 125. Forty percent show H{alpha} in emission. The narrow location in the JHK diagram of the halo C stars is found to differ from that of similar C stars in the above galaxies. The light curves of the Catalina and LINEAR variability databases were exploited to derive the pulsation periods of 66 halo C stars. A few supplementary periods were obtained with the TAROT telescopes. We confirm that the period distribution of the halo strongly resembles that of Fornax, and we found that it is very different from the C stars in the solar neighbourhood. There is a larger proportion of short-period Mira/SRa variables in the halo than in Sgr, but the survey for C stars in this dwarf galaxy is not complete, and the study of their variability needs to be continued to investigate the link between Sgr and the cool halo C stars.
