3,239 results on '"Combes F"'
Search Results
52. HI gas playing hide-and-seek around a powerful FRI-type quasar at z$\sim$2.1
- Author
-
Gupta, N., Srianand, R., Momjian, E., Shukla, G., Combes, F., Krogager, J. -K., Noterdaeme, P., and Petitjean, P.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present optical spectroscopic and milli-arcsecond scale radio continuum observations of the quasar M1540-1453 ($z_{em}$ = 2.104$\pm$0.002) that shows associated HI 21-cm absorption at $z_{abs}$ = 2.1139. At sub-kpc scales, the powerful radio source with 1.4 GHz luminosity of $5.9\times10^{27}$ WHz$^{-1}$ shows Fanaroff-Riley (FR) class I morphology caused by the interaction with dense gas within 70 pc from the AGN. Interestingly, while there are indications for the presence of absorption from low-ionization species like FeII, SiII and SiIII in the optical spectrum, the expected strong damped Ly$\alpha$ absorption is not detected at the redshift of the HI 21-cm absorber. In comparison to typical high-$z$ quasars, the Ly$\alpha$ emission line is much narrower. The `ghostly' nature of the HI Ly$\alpha$ absorber partially covering the broad line region of extent 0.05 pc and the detection of widespread HI 21-cm absorption covering the diffuse radio source (extent $>$425 pc) imply the presence of a large clumpy HI halo -- which may have been blown by the jet-ISM interaction. Further observations are needed to confirm the `ghostly' nature of the Ly$\alpha$ absorber, and obtain a better understanding of the role played by the jet-ISM interaction in shaping the radio morphology of this powerful AGN. The study showcases how joint radio and optical analysis can shed light on gaseous environment and origin of radio morphology in AGN at high redshifts, when these are still the assembly sites of giant galaxies., Comment: 8 pages, 3 figures, Accepted for Publication in ApJ Letters
- Published
- 2022
- Full Text
- View/download PDF
53. Unveiling the Main Sequence to Starburst Transition Region with a Sample of Intermediate Redshift Luminous Infrared Galaxies
- Author
-
Hogan, L., Rigopoulou, D., García-Burillo, S., Alonso-Herrero, A., Barrufet, L., Combes, F., García-Bernete, I., Magdis, G. E., Pereira-Santaella, M., Thatte, N., and Weiß, A.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present a CO(3-2) study of four systems composed of six (ultra) luminous infrared galaxies (U/LIRGs), located at 0.28 < z < 0.44, that straddle the transition region between regular star forming galaxies and starbursts. These galaxies benefit from previous multi-wavelength analysis allowing in depth exploration of an understudied population of U/LIRGs at a time when the universe is experiencing a rapid decline in star formation rate density. We detect CO(3-2) emission in four targets and these galaxies fall between the loci of regular star forming galaxies and starbursts on the Kennicutt-Schmidtt relation. Compared to low luminosity LIRGs and high luminosity ULIRGs at similar redshifts, we find they all have similar molecular gas budgets with the difference in their star formation rates (SFR) driven by the star formation efficiency (SFE). This suggests that at these redshifts large molecular gas reservoirs must coincide with an increased SFE to transition a galaxy into the starburst regime. We studied the structure and kinematics and found our four detections are either interacting or have disturbed morphology which may be driving the SFE. One of the CO(3-2) non-detections has a strong continuum detection, and has been previously observed in H$\alpha$, suggesting an unusual interstellar medium for a ULIRG. We conclude that our sample of transitioning U/LIRGs fill the gap between regular star forming galaxies and starbursts, suggest a continuous change in SFE between these two populations and the increased SFE may be driven by morphology and differing stages of interaction., Comment: 19 pages, 17 figures, accepted for publication in MNRAS
- Published
- 2022
- Full Text
- View/download PDF
54. Gas condensation in Brightest Group Galaxies unveiled with MUSE
- Author
-
Olivares, V., Salome, P., Hamer, S. L., Combes, F., Gaspari, M., Kolokythas, K., O'Sullivan, E., Beckmann, R. S., Babul, A., Polles, F. L., Lehnert, M., Loubser, S. I., Donahue, M., Gendron-Marsolais, M. -L., Lagos, P., Forets, G. Pineau des, Godard, B., Rose, T., Tremblay, G., Ferland, G., and Guillard, P.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
The origin of the cold gas in central galaxies in groups is still a matter of debate. We present Multi-Unit Spectroscopic Explorer (MUSE) observations of 18 optically selected local Brightest Group Galaxies (BGGs) to study the kinematics and distribution of the optical emission-line gas. MUSE observations reveal a distribution of gas morphologies including ten complex networks of filaments extending up to 10 kpc to two compact (<3 kpc) and five extended (>5 kpc) disk-dominated structures. Some rotating disks show rings and elongated structures arising from the central disk. The kinematics of the stellar component is mainly rotation-dominated, which is very different from the disturbed kinematics and distribution found in the filamentary sources. The ionized gas is kinematically decoupled from the stellar component for most systems, suggesting an external origin for the gas. We also find that the Halpha luminosity correlates with the cold molecular mass. By exploring the thermodynamical properties of the hot atmospheres, we find that the filamentary sources and compact disks are found in systems with small central entropy values and tcool/teddy ratios. This suggests that, like for Brightest Cluster Galaxies in cool core clusters, the ionized gas are likely formed from hot halo gas condensations, consistently with the Chaotic Cold Accretion simulations (as shown via the C-ratio, Tat, and k-plot). We note that gaseous rotating disks are more frequent than in BCGs. An explanation for the origin of the gas in those objects is a contribution to gas fueling by mergers or group satellites, as qualitatively hinted by some sources of the present sample. Nonetheless, we discuss the possibility that some extended disks could also be a transition stage in an evolutionary sequence including filaments, extended disks and compact disks, as described by hot gas condensation models of cooling flows., Comment: 38 pages, and 16 figures. Resubmitted to A&A after referee report
- Published
- 2022
- Full Text
- View/download PDF
55. The Close AGN Reference Survey (CARS): No obvious signature of AGN feedback on star formation, but subtle trends
- Author
-
Smirnova-Pinchukova, I., Husemann, B., Davis, T. A., Smith, C. M. A., Singha, M., Tremblay, G. R., Klessen, R. S., Powell, M., Connor, T., Baum, S. A., Combes, F., Croom, S. M., Gaspari, M., Neumann, J., O'Dea, C. P., Pérez-Torres, M., Rosario, D. J., Rose, T., Scharwächter, J., and Winkel, N.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
[Abridged] Active Galactic Nuclei (AGN) are thought to be responsible for the suppression of star formation in massive ~10$^{10}$ M$_\odot$ galaxies. While this process is a key feature in numerical simulations, it is not yet unambiguously confirmed in observational studies. Characterization of the star formation rate (SFR) in AGN host galaxies is challenging as AGN light contaminates most SFR tracers. We aim to obtain and compare SFR estimates from different tracers for AGN host galaxies in the Close AGN Reference Survey (CARS) to provide new observational insights. We construct integrated panchromatic spectral energy distributions (SED) to measure the FIR luminosity as a tracer for the recent (< 100 Myr) SFR. In addition, we use integral-field unit observation of the CARS targets to employ the H$\alpha$ luminosity decontaminated by AGN excitation as a proxy for the current (< 5 Myr) SFR. We find that significant differences in specific SFR of the AGN host galaxies as compared with the larger galaxy population disappear once cold gas mass, in addition to stellar mass, is used to predict the SFR. We identify individual galaxies with a significant difference in their SFR which can be related to a recent enhancement or decline in their SFR history that might be related to various processes including interactions, gas consumption, outflows and AGN feedback. AGN can occur in various stages of galaxy evolution which makes it difficult to relate the SFR solely to the impact of the AGN. We do not find any strong evidence for global positive or negative AGN feedback in the CARS sample. However, there is tentative evidence that 1) the relative orientation of the AGN engine with respect to the host galaxies might alter the efficiency of AGN feedback and 2) the recent SFH is an additional tool to identify rapid changes in galaxy growth driven by the AGN or other processes., Comment: Resubmitted to A&A after minor revision, 24 pages, 10 figures, 3 tables, and appendix. Data available at https://cars.aip.de
- Published
- 2021
- Full Text
- View/download PDF
56. The Close AGN Reference Survey (CARS): Locating the [O III] wing component in luminous local Type 1 AGN
- Author
-
Singha, M., Husemann, B., Urrutia, T., O'Dea, C. P., Scharwächter, J., Gaspari, M., Combes, F., Nevin, R., Terrazas, B. A., Pérez-Torres, M., Rose, T., Davis, T. A., Tremblay, G. R., Neumann, J., Smirnova-Pinchukova, I., and Baum, S. A.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
[Abridged]The strong asymmetry in the optical [O III]$\lambda$5007 emission line is one of the best signatures of AGN-driven warm (~10$^4$ K) ionized gas outflows on host galaxy scales. While large spectroscopic surveys like SDSS have characterized the kinematics of [O III] for large samples of AGN, estimating the associated energetics requires spatially resolving these outflows with, for example, IFU studies. As part of CARS we obtained spatially-resolved IFU spectroscopy for a representative sample of 39 luminous type 1 AGN at 0.01
80 % of the flux associated with a point-like source. We measure <100 pc offsets in the spatial location of the outflow from the AGN nucleus using the spectro-astrometry technique for these sources. For the other 13 AGN, the [O III] wing emission is resolved and possibly extended on kpc scale. We conclude that [O III] wing emission can be compact or extended in an unbiased luminous AGN sample, where both cases are likely to appear. Electron density in the compact [O III] wing regions (median $n_e$~1900 cm$^{-3}$) is nearly a magnitude higher than in the extended ones (median $n_e$~500 cm$^{-3}$). The presence of spatially extended and compact [O III] wing emission is unrelated to the AGN bolometric luminosity and to inclination effects, which means other features such as time delays, or mechanical feedback/radio jets may shape the ionized gas outflow properties., Comment: Accepted for publication in A&A, 19 pages, 13 figures, 3 tables and appendix, data available at https://cars.aip.de - Published
- 2021
- Full Text
- View/download PDF
57. The Close AGN Reference Survey (CARS): IFU survey data and the BH mass dependence of long-term AGN variability
- Author
-
Husemann, B., Singha, M., Scharwächter, J., McElroy, R., Neumann, J., Smirnova-Pinchukova, I., Urrutia, T., Baum, S. A., Bennert, V. N., Combes, F., Croom, S. M., Davis, T. A, Fournier, Y., Galkin, A., Gaspari, M., Enke, H., Krumpe, M., O'Dea, C. P., Pérez-Torres, M., Rose, T., Tremblay, G. R., and Walcher, C. J.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
[Abridged] AGN are thought to be intimately connected with their host galaxies through feeding and feedback processes. A spatially resolved multiwavelength survey is required to map the interaction of AGN with their host galaxies on different spatial scales and different phases of the ISM. The goal of CARS is to obtain the necessary spatially resolved multiwavelength observations for an unbiased sample of local unobscured luminous AGN. We present the overall CARS survey design and the associated wide-field optical IFU spectroscopy for all 41 CARS targets at z<0.06 randomly selected from the Hamburg/ESO survey of luminous unobscured AGN. This data set provides the backbone of CARS and allows us to characterize host galaxy morphologies, AGN parameters, precise systemic redshifts, and ionized gas distributions including excitation conditions, kinematics, and metallicities in unprecedented detail. We focus our study on the size of the ENLR which has been traditionally connected to AGN luminosity. Given the large scatter in the ENLR size-luminosity relation, we performed a large parameter search to identify potentially more fundamental relations. Remarkably, we identified the strongest correlation between the maximum projected ENLR size and the black hole mass, consistent with an $R_\mathrm{ENLR,max}\sim M_\mathrm{BH}^{0.5}$ relationship. We interpret the maximum ENLR size as a timescale indicator of a single BH radiative-efficient accretion episode for which we inferred log(t_AGN) = (0.45+- 0.08)log(M_BH)+1.78 using forward modeling. The extrapolation of our inferred relation toward higher BH masses is consistent with an independent lifetime estimate from the HeII proximity zones around luminous AGN at z~3. While our proposed link between the BH mass and AGN lifetime might be a secondary correlation itself or impacted by unknown biases, it has a few relevant implications if confirmed., Comment: accepted for publication in A&A, 20 pages, 18 figures, 6 tables, data available at https://cars.aip.de
- Published
- 2021
- Full Text
- View/download PDF
58. Dense Molecular Clouds in the Crab Supernova Remnant
- Author
-
Wootten, Alwyn, Bentley, Rory O., Baldwin, J., Combes, F., Fabian, A. C., Ferland, G. J., Loh, E., Salome, P., Shingledecker, C. N., and Castro-Carrizo, A.
- Subjects
Astrophysics - Astrophysics of Galaxies ,Astrophysics - Solar and Stellar Astrophysics - Abstract
Molecular emission was imaged with ALMA from numerous components near and within bright H2-emitting knots and absorbing dust globules in the Crab Nebula. These observations provide a critical test of how energetic photons and particles produced in a young supernova remnant interact with gas, cleanly differentiating between competing models. The four fields targeted show contrasting properties but within them, seventeen distinct molecular clouds are identified with CO emission; a few also show emission from HCO+, SiO and/or SO. These observations are compared with Cloudy models of these knots. It has been suggested that the Crab filaments present an exotic environment in which H2 emission comes from a mostly-neutral zone probably heated by cosmic rays produced in the supernova surrounding a cool core of molecular gas. Our model is consistent with the observed CO J=3-2 line strength. These molecular line emitting knots in the Crab present a novel phase of the ISM representative of many important astrophysical environments., Comment: ApJ in press, comments welcome
- Published
- 2021
- Full Text
- View/download PDF
59. Virgo Filaments II: Catalog and First Results on the Effect of Filaments on galaxy properties
- Author
-
Castignani, G., Vulcani, B., Finn, R. A., Combes, F., Jablonka, P., Rudnick, G., Zaritsky, D., Whalen, K., Conger, K., De Lucia, G., Desai, V., Koopmann, R. A., Moustakas, J., Norman, D. J., and Townsend, M.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Virgo is the nearest galaxy cluster; it is thus ideal for studies of galaxy evolution in dense environments in the local Universe. It is embedded in a complex filamentary network of galaxies and groups, which represents the skeleton of the large scale Laniakea supercluster. Here we assemble a comprehensive catalog of galaxies extending up to ~12 virial radii in projection from Virgo to revisit the Cosmic Web structure around it. This work is the foundation of a series of papers that will investigate the multi-wavelength properties of galaxies in the Cosmic Web around Virgo. We match spectroscopically confirmed sources from several databases and surveys including HyperLeda, NASA Sloan Atlas, NED, and ALFALFA. The sample consists of ~7000 galaxies. By exploiting a tomographic approach, we identify 13 filaments, spanning several Mpc in length. Long > 17 Mpc/h filaments, tend to be thin (< 1 Mpc/h in radius) and with a low density contrast (< 5), while shorter filaments show a larger scatter in their structural properties. Overall, we find that filaments are a transitioning environment between the field and cluster in terms of local densities, galaxy morphologies, and fraction of barred galaxies. Denser filaments have a higher fraction of early type galaxies, suggesting that the morphology-density relation is already in place in the filaments, before galaxies fall into the cluster itself. We release the full catalog of galaxies around Virgo and their associated properties., Comment: 32 pages, version after the proof corrections, ApJS in press
- Published
- 2021
- Full Text
- View/download PDF
60. MALS SALT-NOT survey of MIR-selected powerful radio-bright AGN at 0<z<3.5
- Author
-
Gupta, N., Shukla, G., Srianand, R., Krogager, J-. K., Noterdaeme, P., Baker, A. J., Combes, F., Fynbo, J. P. U., Momjian, E., Hilton, M., Hussain, T., Moodley, K., Petitjean, P., Chen, H. -W., Deka, P., Dutta, R., Jose, J., Jozsa, G. I. G., Kaski, C., Klockner, H. -R., Knowles, K., Sikhosana, S., and Wagenveld, J.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present results of an optical spectroscopic survey using SALT and NOT to build a WISE mid-infrared color-based, dust-unbiased sample of powerful radio-bright ($>$200 mJy at 1.4 GHz) AGN for the MeerKAT Absorption Line Survey (MALS). Our sample has 250 AGN (median $z=1.8$) showing emission lines, 26 with no emission lines, and 27 without optical counterparts. Overall, our sample is fainter ($\Delta i$=0.6 mag) and redder ($\Delta(g-i)$=0.2 mag) than radio-selected quasars, and representative of fainter quasar population detected in optical surveys. About 20% of the sources are narrow line AGN (NLAGN) $-$ 65% of these, at $z < 0.5$ are galaxies without strong nuclear emission, and 10% at $z>1.9$, have emission line ratios similar to radio galaxies. The farthest NLAGN in our sample is M1513$-$2524 ($z_{em}=3.132$), and the largest (size$\sim$330 kpc) is M0909$-$3133 ($z_{em}=0.884$). We discuss in detail 110 AGN at $1.9 < z < 3.5$. Despite representing the radio loudest quasars (median $R$=3685), their Eddington ratios are similar to the SDSS quasars having lower $R$. We detect 4 CIV BALQSOs, all among AGN with least $R$, and highest black hole masses and Eddington ratios. The BAL detection rate ($4^{+3}_{-2}$%) is consistent with that seen in extremely powerful ($L_{1.4GHz}>10^{25}$ WHz$^{-1}$) quasars. Using optical light-curves, radio polarization and $\gamma$-ray detections, we identify 7 high-probability BL Lacs. We also summarize the full MALS footprint to search for HI 21-cm and OH 18-cm lines at $z<2$., Comment: 62 pages, 15 figures and 3 tables; accepted in ApJ (updated the redshift of M1312-2026 to z=0.977)
- Published
- 2021
- Full Text
- View/download PDF
61. The Galaxy Activity, Torus and Outflow Survey (GATOS): II. Torus and polar dust emission in nearby Seyfert galaxies
- Author
-
Alonso-Herrero, A., García-Burillo, S., Hoenig, S. F., García-Bernete, I., Almeida, C. Ramos, González-Martín, O., López-Rodríguez, E., Boorman, P. G., Bunker, A. J., Burtscher, L., Combes, F., Davies, R., Díaz-Santos, T., Gandhi, P., García-Lorenzo, B., Hicks, E. K. S., Hunt, L. K., Ichikawa, K., Imanishi, M., Izumi, T., Labiano, A., Levenson, N. A., Packham, C., Pereira-Santaella, M., Ricci, C., Rigopoulou, D., Roche, P., Rosario, D. J., Rouan, D., Shimizu, T., Stalevski, M., Wada, K., and Williamson, D.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We compare mid-IR and ALMA far-IR images of 12 nearby Seyferts selected from GATOS. The mid-IR unresolved emission contributes more than 60% of the nuclear emission in most galaxies. By contrast, the ALMA 870micron continuum emission is mostly resolved and typically along the torus equatorial direction (Paper I, Garcia-Burillo et al. 2021). The Eddington ratios and nuclear hydrogen column densities NH of half the sample are favorable to launching polar and/or equatorial dusty winds, according to simulations. Six show mid-IR extended emission in the polar direction as traced by the NLR and perpendicular to the ALMA emission. In a few, the nuclear NH might be too high to uplift large quantities of dusty material along the polar direction. Five galaxies have low NH and/or Eddington ratios and thus polar dusty winds are not likely. We generate new CAT3D-WIND disk-wind model images. At low wind-to-disk cloud ratios the far-IR model images have disk- and ring-like morphologies. The X-shape associated with dusty winds is seen better in the far-IR at intermediate-high inclinations for the extended-wind configurations. In most models, the mid-IR emission comes from the inner part of the disk/cone. Extended bi-conical and one-sided polar mid-IR emission is seen in extended-wind configurations and high wind-to-disk cloud ratios. When convolved to our resolution, the model images reproduce qualitative aspects of the observed morphologies. Low-intermediate wind-to-disk ratios are required to account for the large fractions of unresolved mid-IR emission. This work and Paper I provide observational support for the torus+wind scenario. The wind component is more relevant at high Eddington ratios and/or AGN luminosities, and polar dust emission is predicted at NH of up to $10^{24}$cm$^{-2}$. The torus/disk component, on the other hand, prevails at low luminosities and/or Eddington ratios. (Abridged), Comment: 27 pages, 27 figures. Accepted for publication in A&A
- Published
- 2021
- Full Text
- View/download PDF
62. Molecular gas kinematics in the nuclear region of nearby Seyfert galaxies with ALMA
- Author
-
Belete, A. Bewketu, Andreani, P., Fernández-Ontiveros, J. A., Hatziminaoglou, E., Combes, F., Sirressi, M., Slater, R., Ricci, C., Dasyra, K., Cicone, C., Aalto, S., Spinoglio, L., Imanishi, M., and De Medeiros, J. R.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present the analysis of the molecular gas in the nuclear regions of NGC 4968, NGC 4845, and MCG-06-30-15, with the help of ALMA observations of the CO(2-1) emission line. The aim is to determine the kinematics of the gas in the central (~ 1 kpc) region. We use the 3D-Based Analysis of Rotating Object via Line Observations ($^{3D}$BAROLO) and DiskFit softwares. Circular motions dominate the kinematics of the gas in the central discs, mainly in NGC 4845 and MCG-06-30-15, however there is a clear evidence of non-circular motions in the central ($\sim$ 1 kpc) region of NGC 4845 and NGC 4968. The strongest non-circular motion is detected in the inner disc of NGC 4968 with velocity $\sim 115\, \rm{km\,s^{-1}}$. The bisymmetric model is found to give the best-fit for NGC 4968 and NGC 4845. If the dynamics of NGC 4968 is modeled as a corotation pattern just outside of the bar, the bar pattern speed turns out to be at $\Omega_b$ = $52\, \rm{km\,s^{-1}\,kpc^{-1}}$ the corotation is set at 3.5 kpc and the inner Lindblad resonance (ILR) ring at R = 300pc corresponding to the CO emission ring. The 1.2 mm ALMA continuum is peaked and compact in NGC 4968 and MCG-06-30-15, but their CO(2-1) has an extended distribution. Allowing the CO-to-H$_{2}$ conversion factor $\alpha_{CO}$ between 0.8 and 3.2, typical of nearby galaxies of the same type, the molecular mass M(H$_{2}$) is estimated to be $\sim 3-12\times 10^{7} ~{\rm M_\odot}$ (NGC 4968), $\sim 9-36\times 10^{7}~ {\rm M_\odot}$ (NGC 4845), and $\sim 1-4\times 10^{7}~ {\rm M_\odot}$ (MCG-06-30-15). We conclude that the observed non-circular motions in the disc of NGC 4968 and likely that seen in NGC 4845 is due to the presence of the bar in the nuclear region. At the current spectral and spatial resolution and sensitivity we cannot claim any strong evidence in these sources of the long sought feedback/feeding effect due to the AGN presence., Comment: 14 pages, 11 figures, 3 tables, accepted for publication in the Astronomy & Astrophysics (A&A) journal
- Published
- 2021
- Full Text
- View/download PDF
63. SEEDisCS II. Molecular gas in galaxy clusters and their large scale structure: low gas fraction galaxies, the case of CL1301.7$-$1139
- Author
-
Spérone-Longin, D., Jablonka, P., Combes, F., Castignani, G., Krips, M., Rudnick, G., Desjardins, T., Zaritsky, D., Finn, R. A., De Lucia, G., and Desai, V.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
This paper is the second of a series that tackles the properties of molecular gas in galaxies residing in clusters and their related large-scale structures. Out of 21 targeted fields, 19 galaxies were detected in CO(3-2) with the Atacama Large Millimeter Array (ALMA), including two detections within a single field. These galaxies are either bona fide members of the CL1301.7$-$1139 cluster ($z=0.4828$, $\sigma_{cl}=681$ km s$^{-1}$), or located within $\sim 7 \times R_{200}$, its virial radius. They have been selected to sample the range of photometric local densities around CL1301.7$-$1139, with stellar masses above log($M_{\rm star}$) = 10, and to be located in the blue clump of star-forming galaxies derived from the $u$, $g$, and $i$ photometric bands. Unlike previous works, our sample selection does not impose a minimum star formation rate or detection in the far-infrared. As such and as much as possible, it delivers an unbiased view of the gas content of normal star-forming galaxies at $z \sim 0.5$. Our study highlights the variety of paths to star formation quenching, and most likely the variety of physical properties (i.e. temperature, density) of the corresponding galaxy's cold molecular gas. Just as in the case of CL1411.1$-$1148, although to a smaller extent, we identify a number of galaxies with lower gas fraction than classically found in other surveys. These galaxies can still be on the star-forming main sequence. When these galaxies are not inside the cluster virialised region, we provide hints that they are linked to their infall regions within $\sim 4 \times R_{200}$., Comment: 15 pages, 11 figures, accepted for publication in A&A. arXiv admin note: text overlap with arXiv:2012.09592
- Published
- 2021
- Full Text
- View/download PDF
64. The Galaxy Activity, Torus and Outflow Survey (GATOS) I. ALMA images of dusty molecular tori in Seyfert galaxies
- Author
-
García-Burillo, S., Alonso-Herrero, A., Almeida, C. Ramos, González-Martín, O., Combes, F., Usero, A., Hönig, S., Querejeta, M., Hicks, E. K. S., Hunt, L. K., Rosario, D., Davies, R., Boorman, P. G., Bunker, A. J., Burtscher, L., Colina, L., Díaz-Santos, T., Gandhi, P., García-Bernete, I., García-Lorenzo, B., Ichikawa, K., Imanishi, M., Izumi, T., Labiano, A., Levenson, N. A., López-Rodríguez, E., Packham, C., Pereira-Santaella, M., Ricci, C., Rigopoulou, D., Rouan, D., Shimizu, T., Stalevski, M., Wada, K., and Williamson, D.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present the first results of the Galaxy Activity, Torus and Outflow Survey (GATOS), a project aimed at understanding the properties of the dusty molecular tori and their connection to the host galaxy in nearby Seyfert galaxies. Our project expands the range of AGN luminosities and Eddington ratios covered by previous surveys of Seyferts conducted by ALMA and allows us to study the gas feeding and feedback cycle in a combined sample of 19 Seyferts. We used ALMA to obtain new images of the emission of molecular gas and dust using the CO(3-2) and HCO+(4-3) lines as well as their underlying continuum emission at 870 microns with high spatial resolutions (0.1'' ~ 7 - 13 pc) in the CND of 10 nearby (D < 28 Mpc) Seyfert galaxies. Our new ALMA observations detect 870 micron continuum and CO line emission from spatially resolved disks located around the AGN in all the sources. The bulk of the continuum flux can be accounted for by thermal emission from dust in the majority of the targets. For most of the sources the disks show a preponderant orientation perpendicular to the AGN wind axes, as expected for dusty molecular tori. The median diameters and molecular gas masses of the tori are ~ 42 pc, and ~ 6 x 10**5 Msun, respectively. We find a positive correlation between the line-of-sight gas column densities responsible for the absorption of X-rays and the molecular gas column densities derived from CO towards the AGN in our sources. The radial distributions of molecular gas in the CND of our combined sample show signs of nuclear-scale molecular gas deficits. We also detect molecular outflows in the sources that show the most extreme nuclear-scale gas deficits in our sample. These observations find for the first time supporting evidence that the imprint of AGN feedback is more extreme in higher luminosity and/or higher Eddington ratio Seyfert galaxies., Comment: 41 pages, new version revised and accepted by A&A on the 22nd of June 2021
- Published
- 2021
- Full Text
- View/download PDF
65. Are local ULIRGs powered by AGN? The sub-kpc view of the 220 GHz continuum. PUMA II
- Author
-
Pereira-Santaella, M., Colina, L., García-Burillo, S., Lamperti, I., González-Alfonso, E., Perna, M., Arribas, S., Alonso-Herrero, A., Aalto, S., Combes, F., Labiano, A., Piqueras-López, J., Rigopoulou, D., and van der Werf, P.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We analyze high-resolution (400pc) 220GHz continuum and CO(2-1) ALMA observations of a representative sample of 23 local (z<0.165) ULIRG systems (34 individual nuclei) as part of the "Physics of ULIRGs with MUSE and ALMA" (PUMA) project. The deconvolved half-light radii of the 220GHz continuum sources are between <60-350 pc (median 90pc). We associate these regions with the regions emitting the bulk of the infrared luminosity. The good agreement, within a factor of 2, between the 220GHz fluxes and the extrapolation of the infrared gray-body, and the small synchrotron and free-free contributions support this assumption. The cold molecular gas emission sizes, r_CO, are 60-700 pc and are similar in advanced mergers and early interacting systems. On average, r_CO are 2.5 times larger than the continuum. We derive L_IR and cold molecular gas surface densities: log Sigma(L_IR)=11.5-14.3 Lsun/kpc^2 and log Sigma(H2)=2.9-4.2 Msun/pc^2. Assuming that the L_IR is produced by star-formation, this corresponds to median Sigma(SFR)=2500 Msun/yr/kpc^2 which would imply extremely short depletion times, <1-15 Myr, and unphysical SF efficiencies >1 for 70% of the sample. Therefore, this favors the presence of obscured AGN that could dominate the L_IR. We also classify the ULIRG nuclei in two groups: (a) compact nuclei (r<130 pc) with high mid-IR excess emission found in optically classified AGN; and (b) nuclei following a relation with decreasing mid-IR excess for decreasing r. 60% of the interacting nuclei lie in the low end (<130 pc) of this relation, while only 30% of the advanced mergers do so, suggesting that in the early interaction phases the activity occurs in more compact and obscured regions. About two thirds of the nuclei are above the Eddington limit which is consistent with the detection of massive outflows in local ULIRGs and the potential role of radiation pressure in the launching process., Comment: Accepted for publication in A&A
- Published
- 2021
- Full Text
- View/download PDF
66. Excitation mechanisms in the intracluster filaments surrounding Brightest Cluster Galaxies
- Author
-
Polles, F. L., Salomé, P., Guillard, P., Godard, B., Forêts, G. Pineau des, Olivares, V., Beckmann, R. S., Canning, R. E. A., Combes, F., Dubois, Y., Edge, A. C., Fabian, A. C., Ferland, G. J., Hamer, S. L., and Lehnert, M. D.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
The excitation of the filamentary gas structures surrounding giant elliptical galaxies at the center of cool-core clusters, a.k.a BCGs (brightest cluster galaxies), is key to our understanding of active galactic nucleus feedback, and of the impact of environmental and local effects on star formation. We investigate the contribution of the thermal radiation from the cooling flow surrounding BCGs to the excitation of the filaments. We explore the effects of small levels of extra-heating (turbulence), and of metallicity, on the optical and infrared lines. Using the Cloudy code, we model the photoionization and photodissociation of a slab of gas of optical depth AV{\leq}30mag at constant pressure, in order to calculate self-consistently all of the gas phases, from ionized gas to molecular gas. The ionizing source is the EUV and soft X-ray radiation emitted by the cooling gas. We test these models comparing their predictions to the rich multi-wavelength observations, from optical to submillimeter. These models reproduce most of the multi-wavelength spectra observed in the nebulae surrounding the BCGs, not only the LINER-like optical diagnostics: [O iii]{\lambda} 5007 {\AA}/H\b{eta}, [N ii]{\lambda} 6583 {\AA}/H{\alpha} and ([S ii]{\lambda} 6716 {\AA}+[S ii]{\lambda} 6731 {\AA})/H{\alpha} but also the infrared emission lines from the atomic gas. The modeled ro-vib H2 lines also match observations, which indicates that near and mid-IR H2 lines are mostly excited by collisions between H2 molecules and secondary electrons produced naturally inside the cloud by the interaction between the X-rays and the cold gas in the filament. However, there is still some tension between ionized and molecular line tracers (i.e. CO), which requires to optimize the cloud structure and the density of the molecular zone., Comment: 16 pages, 9 figures, 3 tables. Accepted for publication in A&A
- Published
- 2021
- Full Text
- View/download PDF
67. Remarkably high mass and high velocity dispersion of molecular gas associated with a regular, absorption-selected type-I quasar
- Author
-
Noterdaeme, P., Balashev, S., Combes, F., Gupta, N., Srianand, R., Krogager, J. -K., Laursen, P., and Omont, A.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present 3-mm observations of the quasar J0015+1842 at z=2.63 with the NOrthern Extended Millimeter Array (NOEMA). Our data reveals molecular gas, traced via a Gaussian CO(3-2) line, with a remarkably large velocity dispersion (FWHM=1010+/-120 km/s) and corresponding to a total molecular mass MH2~(3.4-17)x10^10 Msun, depending on the adopted CO-to-H2 conversion factor alphaCO=(0.8-4.0) Msun (km/s pc^2)^-1. Assuming the 3-mm continuum emission is thermal, we derive a dust mass of the order of Mdust ~5x10^8 Msun. J0015+1842 is located in the molecular gas-rich region in the IR vs CO line luminosity diagram, in-between the main locus of main-sequence and sub-millimetre galaxies and that of most other AGNs targeted so far for CO measurements. While the large velocity dispersion of the CO line suggests a merging system, J0015+1842 is observed to be a regular, only very moderately dust-reddened (Av~0.3-0.4) type-I quasar from its UV-optical spectrum, from which we infer a mass of the super-massive black hole be around MBH~6x10^8 Msun. We suggest that J0015+1842 is observed at a galaxy evolutionary stage where a massive merger has brought significant amounts of gas towards an actively accreting super-massive black hole (quasar). While the host still contains a large amount of dust and molecular gas with high velocity dispersion, the quasar has already cleared the way towards the observer, likely through powerful outflows as recently revealed by optical observations of the same object. High angular resolution observations of this and similar systems} should help determining better the respective importance of evolution and orientation in the appearance of quasars and their host galaxies and have the potential to investigate early feedback and star-formation processes in galaxies in their quasar phases., Comment: 5 pages, 5 figures, accepted for publication in A\&A
- Published
- 2021
- Full Text
- View/download PDF
68. Evolution of cold gas at 2<z<5: a blind search for HI and OH absorption lines towards mid-infrared color selected radio-loud AGNs
- Author
-
Gupta, N., Srianand, R., Shukla, G., Krogager, J-. K., Noterdaeme, P., Combes, F., Dutta, R., Fynbo, J. P. U., Hilton, M., Momjian, E., Moodley, K., and Petitjean, P.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present results from a spectroscopically blind search for associated and intervening HI 21-cm and OH 18-cm absorption lines towards 88 AGNs at $2\le z\le5$ using the upgraded Giant Metrewave Radio Telescope (uGMRT). The sample of AGNs with 1.4 GHz spectral luminosity in the range, $10^{27 - 29.3}$ W/Hz, is selected using mid-infrared colors and closely resembles the distribution of the underlying quasar population. The search for associated or proximate absorption, defined to be within 3000 km/s of the AGN redshift, led to one HI 21-cm absorption detection (M1540-1453; $z_{abs}$= 2.1139). This is only the fourth known absorption at $z>2$. The detection rate ($1.6^{+3.8}_{-1.4}$%) suggests low covering factor of cold neutral medium (CNM; T$\sim$100 K) associated with these powerful AGNs. The intervening absorption line search, with a sensitivity to detect CNM in damped Ly$\alpha$ systems (DLAs), has comoving absorption path lengths of $\Delta$X = 130.1 and 167.7 for HI and OH, respectively. The corresponding number of absorber per unit comoving path lengths are $\le$0.014 and $\le$0.011, respectively. The former is at least 4.5 times lower than that of DLAs and consistent with the CNM cross-section estimated using H$_2$ and CI absorbers at $z>2$. Our AGN sample is optically fainter compared to the quasars used to search for DLAs in the past. In our optical spectra obtained using the Southern African Large Telescope (SALT) and the Nordic Optical Telescope (NOT), we detect 5 intervening (redshift path$\sim9.3$) and 2 proximate DLAs. This is slightly excessive compared to the statistics based on optically selected quasars. The non-detection of HI 21-cm absorption from these DLAs suggests small CNM covering fraction around galaxies at $z>2$., Comment: 23 pages, 14 figures and 4 tables; accepted in ApJS
- Published
- 2021
- Full Text
- View/download PDF
69. Complex molecules in the Orion Kleinmann-Low nebula
- Author
-
Despois D., Brouillet N., Peng T.-C., Baudry A., Favre C., Combes F., Wlodarczak G., and Guélin M.
- Subjects
Microbiology ,QR1-502 ,Physiology ,QP1-981 ,Zoology ,QL1-991 - Abstract
In the framework of the delivery to the early Earth of extraterrestrial molecules, we have studied complex molecular species toward the Orion Kleinmann-Low nebula. This nebula is rich in molecules as well as in nascent stars and planetary systems. We focus here on HCOOCH3, CH3OCH3 and deuterated methanol. Upper limits on species of prebiotic interest like glycine were also obtained.
- Published
- 2014
- Full Text
- View/download PDF
70. CON-quest: Searching for the most obscured galaxy nuclei
- Author
-
Falstad, N., Aalto, S., König, S., Onishi, K., Muller, S., Gorski, M., Sato, M., Stanley, F., Combes, F., González-Alfonso, E., Mangum, J. G., Evans, A. S., Barcos-Muñoz, L., Privon, G. C., Linden, S. T., Díaz-Santos, T., Martín, S., Sakamoto, K., Harada, N., Fuller, G. A., Gallagher, J. S., van der Werf, P. P., Viti, S., Greve, T. R., García-Burillo, S., Henkel, C., Imanishi, M., Izumi, T., Nishimura, Y., Ricci, C., and Mühle, S.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Some luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) host extremely compact and dusty nuclei. The intense infrared radiation arising from warm dust in these sources is prone to excite vibrational levels of molecules such as HCN. This results in emission from the rotational transitions of vibrationally excited HCN (HCN-vib), with the brightest emission found in compact obscured nuclei (CONs). We aim to establish how common CONs are in the local Universe, and whether their prevalence depends on the luminosity or other properties of the host galaxy. We have conducted an Atacama Large Millimeter/submillimeter Array (ALMA) survey of the rotational J=3-2 transition of HCN-vib in a sample of 46 far-infrared luminous galaxies. Compact obscured nuclei are identified in 38 percent of ULIRGs, 21 percent of LIRGs, and 0 percent of lower luminosity galaxies. We find no dependence on the inclination of the host galaxy, but strong evidence of lower IRAS 25 to 60 {\mu}m flux density ratios (f25/f60) in CONs compared to the rest of the sample. Furthermore, we find that CONs have stronger silicate features (s9.7{\mu}m) but similar PAH equivalent widths (EQW6.2{\mu}m) compared to other galaxies. In the local Universe, CONs are primarily found in (U)LIRGs. High resolution continuum observations of the individual nuclei are required to determine if the CON phenomenon is related to the inclinations of the nuclear disks. The lower f25/f60 ratios in CONs as well as the results for the mid-infrared diagnostics investigated are consistent with large dust columns shifting the nuclear radiation to longer wavelengths, making the mid- and far-infrared "photospheres" significantly cooler than the interior regions. To assess the importance of CONs in the context of galaxy evolution, it is necessary to extend this study to higher redshifts where (U)LIRGs are more common., Comment: 16 pages, 11 figures, Accepted for publication in Astronomy and Astrophysics
- Published
- 2021
- Full Text
- View/download PDF
71. A Massive, Clumpy Molecular Gas Distribution and Displaced AGN in Zw 3146
- Author
-
Vantyghem, A. N., McNamara, B. R., O'Dea, C. P., Baum, S. A., Combes, F., Edge, A. C., Fabian, A. C., McDonald, M., Nulsen, P. E. J., Russell, H. R., and Salome, P.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present a recent ALMA observation of the CO(1-0) line emission in the central galaxy of the Zw 3146 galaxy cluster ($z=0.2906$). We also present updated X-ray cavity measurements from archival Chandra observations. The $5\times 10^{10}\,M_{\odot}$ supply of molecular gas, which is confined to the central 4 kpc, is marginally resolved into three extensions that are reminiscent of the filaments observed in similar systems. No velocity structure that would be indicative of ordered motion is observed. The three molecular extensions all trail X-ray cavities, and are potentially formed from the condensation of intracluster gas lifted in the wakes of the rising bubbles. Many cycles of feedback would be require to account for the entire molecular gas reservoir. The molecular gas and continuum source are mutually offset by 2.6 kpc, with no detected line emission coincident with the continuum source. It is the molecular gas, not the continuum source, that lies at the gravitational center of the brightest cluster galaxy. As the brightest cluster galaxy contains possible tidal features, the displaced continuum source may correspond to the nucleus of a merging galaxy. We also discuss the possibility that a gravitational wave recoil following a black hole merger may account for the displacement., Comment: Accepted to ApJ. 12 pages, 9 figures
- Published
- 2021
- Full Text
- View/download PDF
72. Virgo Filaments I: Processing of gas in cosmological filaments around the Virgo cluster
- Author
-
Castignani, G., Combes, F., Jablonka, P., Finn, R. A., Rudnick, G., Vulcani, B., Desai, V., Zaritsky, D., and Salomé, P.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Galaxies have different morphology, gas content and star formation rate (SFR) in dense environments like galaxy clusters. The impact of environmental density extends to several virial radii, and galaxies are pre-processed in filaments and groups, before falling into the cluster. Our goal is to quantify this pre-processing, in terms of gas content and SFR, as a function of density in cosmic filaments. We have observed the two first CO transitions in 163 galaxies with the IRAM-30m telescope, and added 82 more measurements from the literature, for a sample of 245 galaxies in the filaments around Virgo. We gathered HI-21cm measurements from the literature, and observed 69 galaxies with the Nan\c{c}ay telescope, to complete our sample. We compare our filament galaxies with comparable samples from the Virgo cluster and with the isolated galaxies of the AMIGA sample. We find a progression from field galaxies to filament and cluster ones for decreasing SFR, increasing fraction of galaxies in the quenching phase, increasing proportion of early-type galaxies and decreasing gas content. Galaxies in the quenching phase, defined as having SFR below 1/3 of the main sequence rate, are only between 0-20\% in the isolated sample, while they are 20-60\% in the filaments and 30-80\% in the Virgo cluster. Processes that lead to star formation quenching are already at play in filaments. They depend mostly on the local galaxy density, while the distance to the filament spine is a secondary parameter. While the HI to stellar mass ratio decreases with local density by ~1 dex in the filaments, and ~2 dex in Virgo with respect to the field, the decrease is much less for the H$_2$ to stellar mass ratio. As the environmental density increases, the gas depletion time decreases, since the gas content decreases faster than the SFR. This suggests that gas depletion significantly precedes star formation quenching., Comment: 26 pages, plus 90 pages of supplementary material, A&A in press, minor corrections after the proofs
- Published
- 2021
- Full Text
- View/download PDF
73. PKS1830-211: OH and HI at z=0.89 and the first MeerKAT UHF spectrum
- Author
-
Combes, F., Gupta, N., Muller, S., Balashev, S., Jozsa, G. I. G., Srianand, R., Momjian, E., Noterdaeme, P., Kloeckner, H. -R., Baker, A. J., Boettcher, E., Bosma, A., Chen, H. -W., Dutta, R., Jagannathan, P., Jose, J., Knowles, K., Krogager, J-. K., Kulkarni, V. P., Moodley, K., Pandey, S., Petitjean, P., and Sekhar, S.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
The Large Survey Project (LSP) "MeerKAT Absorption Line Survey" (MALS) is a blind HI 21-cm and OH 18-cm absorption line survey in the L- and UHF-bands, with the primary goal to better determine the occurrence of atomic and molecular gas in the circum-galactic and inter-galactic medium, and its redshift evolution. Here we present the first results using the UHF-band, obtained towards the strongly lensed radio source PKS1830, detecting absorption in the lens galaxy. With merely 90min of data acquired on-source for science verification and processed using the Automated Radio Telescope Imaging Pipeline (ARTIP), we detect in absorption the known HI 21-cm and OH 18-cm main lines at z=0.89 at an unprecedented signal-to-noise ratio (4000 in the continuum, with 6km/s channels). For the first time we report the detection at z=0.89 of OH satellite lines, so far not detected at z $>$ 0.25. We decompose the OH lines into a thermal and a stimulated contribution, where the 1612 and 1720MHz lines are conjugate. The total OH 1720MHz emission line luminosity is 6100Lsun. This is the most luminous known 1720MHz maser line. The absorption components of the different images of the background source sample different light paths in the lensing galaxy, and their weights in the total absorption spectrum are expected to vary in time, on daily and monthly time scales. We compare our normalized spectra with those obtained more than 20 yrs ago, and find no variation. We interpret the absorption spectra with the help of a lens galaxy model, derived from an N-body hydro-dynamical simulation, with a morphology similar to its optical HST image. It is possible to reproduce the observations without invoking any central gas outflows. There are, however, distinct and faint high-velocity features, most likely high-velocity clouds. These clouds may contribute to broaden the HI and OH spectra., Comment: 13 pages, 11 figures, accepted in Astronomy and Astrophysics
- Published
- 2021
- Full Text
- View/download PDF
74. SEEDisCS I. Molecular gas in galaxy clusters and their large scale structure: the case of CL1411.1$-$1148 at $z\sim0.5$
- Author
-
Spérone-Longin, D., Jablonka, P., Combes, F., Castignani, G., Krips, M., Rudnick, G., Zaritsky, D., Finn, R. A., De Lucia, G., and Desai, V.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We investigate how the galaxy reservoirs of molecular gas fuelling star formation are transformed while the host galaxies infall onto galaxy cluster cores. As part of the Spatially Extended ESO Distant Cluster Survey (SEEDisCS), we present CO(3-2) observations of 27 star-forming galaxies obtained with the Atacama Large Millimeter Array (ALMA). These sources are located inside and around CL1411.1$-$1148 at $z=0.5195$, within five times the cluster virial radius. These targets were selected to have stellar masses M$_{\rm star}$), colours, and magnitudes similar to those of a field comparison sample at similar redshift drawn from the Plateau de Bure high-$z$ Blue Sequence Survey (PHIBSS2). We compare the cold gas fraction ($\mu_{\rm H_2}=$ M$_{\rm H_2}$/M$_{\rm star}$), specific star formation rates (SFR/M$_{\rm star}$) and depletion timescales ($t_{\rm depl}=$ M$_{\rm H_2}$/SFR) of our main-sequence galaxies to the PHIBSS2 subsample. While the most of our galaxies (63\%) are consistent with PHIBSS2, the remainder fall below the relation between $\mu_\mathrm{H_2}$ and M$_{\rm star}$ of the PHIBSS2 galaxies at $z\sim0.5$. These low-$\mu_\mathrm{H_2}$ galaxies are not compatible with the tail of a Gaussian distribution, hence they correspond to a new population of galaxies with normal SFRs but low gas content and low depletion times ($\lesssim 1$ Gyr), absent from previous surveys. We suggest that the star formation activity of these galaxies has not yet been diminished by their low fraction of cold molecular gas., Comment: 17 pages, 12 figures, 2 tables, accepted for publication in A&A
- Published
- 2020
- Full Text
- View/download PDF
75. Black hole feeding and star formation in NGC 1808
- Author
-
Audibert, A., Combes, F., García-Burillo, S., Hunt, L., Eckart, A., Aalto, S., Casasola, V., Boone, F., Krips, M., Viti, S., Muller, S., Dasyra, K., van der Werf, P., and Martín, S.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We report on Atacama Large Millimeter Array (ALMA) observations of CO(3-2) emission in the Seyfert2/starburst galaxy NGC1808, at a spatial resolution of 4pc. Our aim is to investigate the morphology and dynamics of the gas inside the central 0.5kpc and to probe the nuclear feeding and feedback phenomena. We discovered a nuclear spiral of radius 1"=45pc. Within it, we found a decoupled circumnuclear disk or molecular torus of a radius of 0.13"=6pc. The HCN(4-3) and HCO$\rm^+$(4-3) and CS(7-6) dense gas line tracers were simultaneously mapped and detected in the nuclear spiral and they present the same misalignment in the molecular torus. At the nucleus, the HCN/HCO$^+$ and HCN/CS ratios indicate the presence of an active galactic nucleus (AGN). The molecular gas shows regular rotation, within a radius of 400pc, except for the misaligned disk inside the nuclear spiral arms. The computations of the torques exerted on the gas by the barred stellar potential reveal that the gas within a radius of 100pc is feeding the nucleus on a timescale of five rotations or on an average timescale of ~60Myr. Some non-circular motions are observed towards the center, corresponding to the nuclear spiral arms. We cannot rule out that small extra kinematic perturbations could be interpreted as a weak outflow attributed to AGN feedback. The molecular outflow detected at $\geqslant$250pc in the NE direction is likely due to supernovae feedback and it is connected to the kpc-scale superwind., Comment: 15 pages, 18 figures, accepted to A&A. arXiv admin note: text overlap with arXiv:1905.01979
- Published
- 2020
- Full Text
- View/download PDF
76. Exploring the hot gaseous halo around an extremely massive and relativistic jet launching spiral galaxy with XMM-Newton
- Author
-
Mirakhor, M. S., Walker, S. A., Bagchi, J., Fabian, A. C., Barth, A. J., Combes, F., Dabhade, P., Ho, L. C., and Pandge, M. B.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present a deep XMM-Newton observation of the extremely massive, rapidly rotating, relativistic-jet-launching spiral galaxy 2MASX J23453268-0449256. Diffuse X-ray emission from the hot gaseous halo around the galaxy is robustly detected out to a radius of 160 kpc, corresponding roughly to 35 per cent of the virial radius ($\approx 450$ kpc). We fit the X-ray emission with the standard isothermal $\beta$ model, and it is found that the enclosed gas mass within 160 kpc is $1.15_{-0.24}^{+0.22} \times 10^{11} \, \rm{M}_{\odot}$. Extrapolating the gas mass profile out to the virial radius, the estimated gas mass is $8.25_{-1.77}^{+1.62} \times 10^{11} \, \rm{M}_{\odot}$, which makes up roughly 65 per cent of the total baryon mass content of the galaxy. When the stellar mass is considered and accounting for the statistical and systematic uncertainties, the baryon mass fraction within the virial radius is $0.121_{-0.043}^{+0.043}$, in agreement with the universal baryon fraction. The baryon mass fraction is consistent with all baryons falling within $r_{200}$, or with only half of the baryons falling within $r_{200}$. Similar to the massive spiral galaxies NGC 1961 and NGC 6753, we find a low value for the metal abundance of $\approx 0.1 {\rm{Z}}_{\odot}$, which appears uniform with radius. We also detect diffuse X-ray emission associated with the northern and southern lobes, possibly attributed to inverse Compton scattering of cosmic microwave background photons. The estimated energy densities of the electrons and magnetic field in these radio lobes suggest that they are electron-dominated by a factor of 10$-$200, depending on the choice of the lower cut-off energy of the electron spectrum., Comment: 11 pages, 10 figures, 4 tables. Accepted for publication in MNRAS
- Published
- 2020
- Full Text
- View/download PDF
77. A Virgo Environmental Survey Tracing Ionised Gas Emission. VESTIGE VIII. Bridging the cluster-ICM-galaxy evolution at small scales
- Author
-
Longobardi, A., Boselli, A., Fossati, M., Villa-Vélez, J. A., Bianchi, S., Casasola, V., Sarpa, E., Combes, F., Hensler8, G., Burgarella, D., Schimd, C., Nanni, A., Côté, P., Buat1, V., Amram, P., Ferrarese, L., Braine, J., Trinchieri, G., Boissier, S., Boquien, M., Andreani, P., Gwyn, S., and Cuillandre, J. C.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We measure FIR emission from tails of stripped dust following the ionised and atomic gas components in galaxies undergoing ram pressure stripping. We study the dust-to-gas relative distribution and mass ratio in the stripped interstellar medium and relate them to those of the intra-cluster medium, thus linking the cluster-ICM-galaxy evolution at small-scales. The galaxy sample consists of three Scd Virgo galaxies with stellar masses in the range $10^9\lesssim \mathrm{M_{*}} \lesssim 10^{10}\, \mathrm{M_{\odot}}$, and within 1 Mpc from the cluster centre, namely NGC 4330, NGC 4522, and NGC 4654. Through the analysis of VESTIGE H$\alpha$, $Herschel$ SPIRE far-infrared, and VIVA HI data, we trace the spatial distribution of the tails and infer the dust and gas masses from the measured far-infrared 250 $\mu$m and HI flux densities. Dust-to-gas mass ratios (DGRs) in the tails are analysed as a function of the galaxy mass, metallicity, and dust temperature. Along the stripped component, the dust distribution closely follows the HI and H$\alpha$ emitting gas, all extending beyond the optical disc. In these regions, the DGRs are $2.0\pm0.6\times10^{-3}$, $0.7\pm0.1\times10^{-3}$, and $0.4\pm0.03\times10^{-3}$, for NGC 4330, NGC 4522, and NGC 4654, respectively, i.e. up to a factor of 15 less than the values measured in the main body of nearby galaxies. We also find a negative trend in the DGR as a function of the metallicity that can be explained in terms of a dust component more centrally concentrated in more metal-rich systems. Together with the finding that the stripped dust is cold, $T_{d} \lesssim 25\, K$, our results support an outside-in stripping scenario of the galaxy interstellar medium. This study shows that ram pressure stripping is a key mechanism in the building up of the Virgo intra-cluster component injecting dust grains into the ICM, thus contributing to its metal enrichment., Comment: 15 pages, 7 images, 4 tables. Accepted on A\&A
- Published
- 2020
- Full Text
- View/download PDF
78. MeerKAT HI commissioning observations of MHONGOOSE galaxy ESO 302-G014
- Author
-
de Blok, W. J. G., Athanassoula, E., Bosma, A., Combes, F., English, J., Heald, G. H., Kamphuis, P., Koribalski, B. S., Meurer, G. R., Román, J., Sardone, A., Verdes-Montenegro, L., Bigiel, F., Brinks, E., Chemin, L., Fraternali, F., Jarrett, T., Kleiner, D., Maccagni, F. M., Pisano, D. J., Serra, P., Spekkens, K., Amram, P., Carignan, C., Dettmar, R-J., Gibson, B. K., Holwerda, B. W., Józsa, G. I. G, Lucero, D. M., Oosterloo, T. A., Ramaila, A. J. T., Ramatsoku, M., Sheth, K., Walter, F., Wong, O. I., Zijlstra, A. A., Bloemen, S., Groot, P. J., Poole, R. Le, Klein-Wolt, M., Körding, E. G., McBride, V. A., Paterson, K., Pieterse, D. L. A., Vreeswijk, P., and Woudt, P. A.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present the results of three commissioning HI observations obtained with the MeerKAT radio telescope. These observations make up part of the preparation for the forthcoming MHONGOOSE nearby galaxy survey, which is a MeerKAT large survey project that will study the accretion of gas in galaxies and the link between gas and star formation. We used the available HI data sets, along with ancillary data at other wavelengths, to study the morphology of the MHONGOOSE sample galaxy, ESO 302-G014, which is a nearby gas-rich dwarf galaxy. We find that ESO 302-G014 has a lopsided, asymmetric outer disc with a low column density. In addition, we find a tail or filament of HI clouds extending away from the galaxy, as well as an isolated HI cloud some 20 kpc to the south of the galaxy. We suggest that these features indicate a minor interaction with a low-mass galaxy. Optical imaging shows a possible dwarf galaxy near the tail, but based on the current data, we cannot confirm any association with ESO 302-G014. Nonetheless, an interaction scenario with some kind of low-mass companion is still supported by the presence of a significant amount of molecular gas, which is almost equal to the stellar mass, and a number of prominent stellar clusters, which suggest recently triggered star formation. These data show that MeerKAT produces exquisite imaging data. The forthcoming full-depth survey observations of ESO 302-G014 and other sample galaxies will, therefore, offer insights into the fate of neutral gas as it moves from the intergalactic medium onto galaxies., Comment: Accepted for publication in Astronomy and Astrophysics
- Published
- 2020
- Full Text
- View/download PDF
79. ALMA resolves the remarkable molecular jet and rotating wind in the extremely radio-quiet galaxy NGC 1377
- Author
-
Aalto, S., Falstad, N., Muller, S., Wada, K., Gallagher, J. S., König, S., Sakamoto, K., Vlemmings, W., Ceccobello, C., Dasyra, K., Combes, F., García-Burillo, S., Oya, Y., Martín, S., van der Werf, P., Evans, A. S., and Kotilainen, J.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Submillimetre and millimetre observations are important in probing the properties of the molecular gas and dust around obscured active galactic nuclei (AGNs) and their feedback. With very high-resolution (0."02x0."03 (2x3 pc)) ALMA 345 GHz observations of CO 3-2, HCO$^+$ 4-3, HCN 4-3 $\nu_2$=1$f$, and continuum we have studied the molecular outflow and nucleus of the extremely radio-quiet lenticular galaxy NGC1377. The outflow is resolved, revealing a 150 pc long, clumpy, high-velocity, collimated molecular jet. The molecular emission is emerging from the spine of the jet with an average diameter of 3-7 pc. A narrow-angle, rotating molecular wind surrounds the jet and is enveloped by a larger-scale, slower CO-emitting structure. The jet and narrow wind are turbulent ($\sigma>$40 kms$^{-1}$) and have steep radial gas excitation gradients. The jet shows velocity reversals that we propose are caused by precession, or episodic directional changes. We suggest that an important process powering the outflow is magneto-centrifugal driving. In contrast, the large-scale CO-envelope may be a slow wind, or cocoon that stems from jet-wind interactions. An asymmetric, nuclear r$\sim$2 pc and hot (>180 K) dust structure with a high molecular column density, N(H$_2$)$\sim1.8 \times 10^{24}$ cm$^{-2}$, is detected in continuum and vibrationally excited HCN. Its luminosity is likely powered by a buried AGN. The mass of the supermassive black hole (SMBH) is estimated to $\sim9\times10^6$ M$_\odot$ and the SMBH of NGC1377 appears to be at the end of an intense phase of accretion. The nuclear growth may be fuelled by low-angular momentum gas inflowing from gas ejected in the molecular jet and wind. Such a feedback-loop of cyclic accretion and outflows would be an effective process in growing the nuclear SMBH. This result invites new questions as to SMBH growth processes in obscured, dusty galaxies., Comment: 16 pages, 12 figures, accepted for publication in Astronomy and Astrophysics. Updated affiliations, added reference
- Published
- 2020
- Full Text
- View/download PDF
80. Blind HI and OH absorption line search: first results with MALS and uGMRT processed using ARTIP
- Author
-
Gupta, N., Jagannathan, P., Srianand, R., Bhatnagar, S., Noterdaeme, P., Combes, F., Petitjean, P., Jose, J., Pandey, S., Kaski, C., Baker, A. J., Balashev, S. A., Boettcher, E., Chen, H. -W., Cress, C., Dutta, R., Goedhart, S., Heald, G., Józsa, G. I. G., Kamau, E., Kamphuis, P., Kerp, J., Klöckner, H. -R., Knowles, K., Krishnan, V., Krogager, J-. K., Kulkarni, V. P., Momjian, E., Moodley, K., Passmoor, S., Schröeder, A., Sekhar, S., Sikhosana, S., Wagenveld, J., and Wong, O. I.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present details of the Automated Radio Telescope Imaging Pipeline (ARTIP) and results of a sensitive blind search for HI and OH absorbers at $z<0.4$ and $z<0.7$, respectively. ARTIP is written in Python 3.6, extensively uses the Common Astronomy Software Application (CASA) tools and tasks, and is designed to enable the geographically-distributed MeerKAT Absorption Line Survey (MALS) team to collaboratively process large volumes of radio interferometric data. We apply it to the first MALS dataset obtained using the 64-dish MeerKAT radio telescope and 32K channel mode of the correlator. With merely 40 minutes on target, we present the most sensitive spectrum of PKS1830-211 ever obtained and characterize the known HI ($z=0.19$) and OH ($z=0.89$) absorbers. We further demonstrate ARTIP's capabilities to handle realistic observing scenarios by applying it to a sample of 72 bright radio sources observed with the upgraded Giant Metrewave Radio Telescope (uGMRT) to blindly search for HI and OH absorbers. We estimate the numbers of HI and OH absorbers per unit redshift to be $n_{21}(z\sim0.18)<$0.14 and $n_{\rm OH}(z\sim0.40)<$0.12, respectively, and constrain the cold gas covering factor of galaxies at large impact parameters (50 kpc $<\rho<$ 150 kpc) to be less than 0.022. Due to the small redshift path, $\Delta z\sim$13 for HI with column density$>5.4\times10^{19}$ cm$^{-2}$, the survey has probed only the outskirts of star-forming galaxies at $\rho>30$ kpc. MALS with the expected $\Delta z\sim10^{3-4}$ will overcome this limitation and provide stringent constraints on the cold gas fraction of galaxies in diverse environments over $0
- Published
- 2020
- Full Text
- View/download PDF
81. ALMA observations of CS in NGC 1068: chemistry and excitation
- Author
-
Scourfield, M., Viti, S., Garcia-Burillo, S., Saintonge, A., Combes, F., Fuente, A., Henkel, C., Alonso-Herrero, A., Harada, N., Takano, S., Nakajima, T., Martin, S., Krips, M., van der Werf, P. P., Aalto, S., Usero, A., and Kohno, K.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present results from Atacama Large Millimeter/submillimeter Array (ALMA) observations of CS from the nearby galaxy NGC 1068 ($\sim14$ Mpc). This Seyfert 2 barred galaxy possesses a circumnuclear disc (CND, $r\sim200$ pc) and a starburst ring (SB ring, $r\sim1.3$ kpc). These high-resolution maps ($\sim0.5$", $\sim35$ pc) allow us to analyse specific sub-regions in the galaxy and investigate differences in line intensity ratios and physical conditions, particularly those between the CND and SB ring. Local thermodynamic equilibrium (LTE) analysis of the gas is used to calculate CS densities in each sub-region, followed by non-LTE analysis conducted using the radiative transfer code RADEX to fit observations and constrain gas temperature, CS column density and hydrogen density. Finally, the chemical code UCLCHEM is used to reconstruct the gas, allowing an insight into its origin and chemical history. The density of hydrogen in the CND is found to be $\geq10^5$ cm$^{-2}$, although exact values vary, reaching $10^6$ cm$^{-2}$ at the AGN. The conditions in the two arms of the SB ring appear similar to one another, though the density found ($\sim10^4$ cm$^{-2}$) is lower than in the CND. The temperature in the CND increases from east to west, and is also overall greater than found in the SB ring. These modelling methods indicate the requirement for multi-phase gas components in order to fit the observed emission over the galaxy. A larger number of high resolution transitions across the SLED may allow for further constraining of the conditions, particularly in the SB ring., Comment: 32 pages, 19 figures, 6 tables, accepted for publication in MNRAS
- Published
- 2020
- Full Text
- View/download PDF
82. Cold molecular gas and PAH emission in Seyfert galaxies
- Author
-
Alonso-Herrero, A., Pereira-Santaella, M., Rigopoulou, D., Garcia-Bernete, I., Garcia-Burillo, S., Dominguez-Fernandez, A. J., Combes, F., Davies, R. I., Diaz-Santos, T., Esparza-Arredondo, D., Gonzalez-Martin, O., Hernan-Caballero, A., Hicks, E. K. S., Hoenig, S. F., Levenson, N. A., Almeida, C. Ramos, Roche, P. F., and Rosario, D.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We investigate the relation between the detection of the $11.3\,\mu$m PAH feature in the nuclear ($\sim 24-230\,$pc) regions of 22 nearby Seyfert galaxies and the properties of the cold molecular gas. For the former we use ground-based (0.3-0.6" resolution) mid-infrared (mid-IR) spectroscopy. The cold molecular gas is traced by ALMA and NOEMA high (0.2-1.1") angular resolution observations of the CO(2-1) transition. Galaxies with a nuclear detection of the $11.3\,\mu$m PAH feature contain more cold molecular gas (median $1.6\times 10^7\,M_\odot$) and have higher column densities ($N({\rm H}_2) = 2 \times 10^{23}\,{\rm cm}^{-2}$) over the regions sampled by the mid-IR slits than those without a detection. This suggests that molecular gas plays a role in shielding the PAH molecules in the harsh environments of Seyfert nuclei. Choosing the PAH molecule naphthalene as an illustration, we compute its half-life in the nuclear regions of our sample when exposed to 2.5keV hard X-ray photons. We estimate shorter half-lives for naphthalene in nuclei without a $11.3\,\mu$m PAH detection than in those with a detection. The Spitzer/IRS PAH ratios on circumnuclear scales ($\sim$ 4" $\sim$ 0.25-1.3kpc) are in between model predictions for neutral and partly ionized PAHs. However, Seyfert galaxies in our sample with the highest nuclear H$_2$ column densities are not generally closer to the neutral PAH tracks. This is because in the majority of our sample galaxies, the CO(2-1) emission in the inner $\sim$ 4" is not centrally peaked and in some galaxies traces circumnuclear sites of strong star formation activity. Spatially resolved observations with the MIRI medium-resolution spectrograph (MRS) on the James Webb Space Telescope will be able to distinguish the effects of an active galactic nucleus (AGN) and star formation on the PAH emission in nearby AGN., Comment: Accepted for publication in A&A
- Published
- 2020
- Full Text
- View/download PDF
83. A molecular absorption line survey toward the AGN of Hydra-A
- Author
-
Rose, Tom, Edge, A. C., Combes, F., Hamer, S., McNamara, B. R., Russell, H., Gaspari, M., Salomé, P., Sarazin, C., Tremblay, G. R., Baum, S. A., Bremer, M. N., Donahue, M., Fabian, A. C., Ferland, G., Nesvadba, N., O'Dea, C., Oonk, J. B. R., and Peck, A. B.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present Atacama Large Millimeter/submillimeter Array observations of the brightest cluster galaxy Hydra-A, a nearby ($z=0.054$) giant elliptical galaxy with powerful and extended radio jets. The observations reveal CO(1-0), CO(2-1), $^{13}$CO(2-1), CN(2-1), SiO(5-4), HCO$^{+}$(1-0), HCO$^{+}$(2-1), HCN(1-0), HCN(2-1), HNC(1-0) and H$_{2}$CO(3-2) absorption lines against the galaxy's bright and compact active galactic nucleus. These absorption features are due to at least 12 individual molecular clouds which lie close to the centre of the galaxy and have velocities of approximately $-50$ to $+10$ km/s relative to its recession velocity, where positive values correspond to inward motion. The absorption profiles are evidence of a clumpy interstellar medium within brightest cluster galaxies composed of clouds with similar column densities, velocity dispersions and excitation temperatures to those found at radii of several kpc in the Milky Way. We also show potential variation in a $\sim 10$ km/s wide section of the absorption profile over a two year timescale, most likely caused by relativistic motions in the hot spots of the continuum source which change the background illumination of the absorbing clouds., Comment: Accepted for publication in MNRAS
- Published
- 2020
- Full Text
- View/download PDF
84. Molecular gas in CLASH brightest cluster galaxies at $z\sim0.2-0.9$
- Author
-
Castignani, G., Pandey-Pommier, M., Hamer, S. L., Combes, F., Salomé, P., Freundlich, J., and Jablonka, P.
- Subjects
Astrophysics - Astrophysics of Galaxies ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Brightest cluster galaxies (BCGs) are excellent laboratories to study galaxy evolution in dense Mpc-scale environments. We have observed in CO(1-0), CO(2-1), CO(3-2), or CO(4-3), with the IRAM-30m, 18 BCGs at $z\sim0.2-0.9$ that are drawn from the CLASH survey. Our sample includes RX1532, which is our primary target, being among the BCGs with the highest star formation rate (SFR$\gtrsim100~M_\odot$/yr) in the CLASH sample. We unambiguously detected both CO(1-0) and CO(3-2) in RX1532, yielding a large reservoir of molecular gas, $M_{H_2}=(8.7\pm1.1)\times10^{10}~M_\odot$, and a high level of excitation $r_{31}=0.75\pm0.12$. A morphological analysis of the HST I-band image of RX1532 reveals the presence of clumpy substructures both within and outside the half-light radius $r_e=(11.6\pm0.3)$ kpc, similarly to those found independently both in ultraviolet and in H$_\alpha$ in previous work. We tentatively detected CO(1-0) or CO(2-1) in four other BCGs, with molecular gas reservoirs in the range $M_{H_2}=2\times10^{10-11} M_\odot$. For the remaining 13 BCGs we set robust upper limits of $M_{H_2}/M_\star\lesssim0.1$, which are among the lowest molecular gas to stellar mass ratios found for distant ellipticals and BCGs. By comparison with distant cluster galaxies observed in CO our study shows that RX1532 ($M_{H_2}/M_\star = 0.40\pm0.05$) belongs to the rare population of star forming and gas-rich BCGs in the distant universe. By using available X-ray based estimates of the central intra-cluster medium entropy, we show that the detection of large reservoirs of molecular gas $M_{H_2}\gtrsim10^{10}~M_\odot$ in distant BCGs is possible when the two conditions are met: i) high SFR and ii) low central entropy, which favors the condensation and the inflow of gas onto the BCGs themselves, similarly to what has been previously found for some local BCGs., Comment: 16 pages, 8 figures, 4 tables, A&A in press
- Published
- 2020
- Full Text
- View/download PDF
85. Circum-nuclear molecular disks: role in AGN fueling and feedback
- Author
-
Combes, F.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Gas inflows fueling AGN are now traceable at high-resolution with ALMA and NOEMA. Dynamical mechanisms are essential to exchange angular momentum and drive the gas to the super-massive black hole. While at 100pc scale, the gas is sometimes stalled in nuclear rings, recent observations reaching 10pc scale (50mas), inside the sphere of influence of the black hole, may bring smoking gun evidence of fueling, within a randomly oriented nuclear molecular disk. AGN feedback is also observed, in the form of narrow and collimated molecular outflows, which point towards the radio mode, or entrainment by a radio jet. Precession has been observed in a molecular outflow, indicating the precession of the radio jet. One of the best candidates for precession is the Bardeen-Petterson effect at small scale, which exerts a torque on the accreting material, and produces an extended disk warp. The misalignment between the inner and large-scale disk, enhances the coupling of the AGN feedback, since the jet sweeps a large part of the molecular disk., Comment: 6 pages, 3 figures, Proceedings of IAUS 359, Storchi-Bergmann et al. ed
- Published
- 2020
- Full Text
- View/download PDF
86. Detection of deuterated molecules, but not of lithium hydride, in the z=0.89 absorber toward PKS1830-211
- Author
-
Muller, S., Roueff, E., Black, J. H., Gerin, M., Guelin, M., Menten, K. M., Henkel, C., Aalto, S., Combes, F., Martin, S., and Marti-Vidal, I.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Deuterium and lithium are light elements of high cosmological and astrophysical importance. In this work we report the first detection of deuterated molecules and a search for lithium hydride, 7LiH, at redshift z=0.89 in the spiral galaxy intercepting the line of sight to the quasar PKS1830-211. We used ALMA to observe several submillimeter lines of ND, NH2D, and HDO, and their related isotopomers NH2, NH3, and H2^18O, in absorption against the southwest image of the quasar, allowing us to derive XD/XH abundance ratios. The absorption spectra mainly consist of two distinct narrow velocity components for which we find remarkable differences. One velocity component shows XD/XH abundances that is about 10 times larger than the primordial elemental D/H ratio, and no variability of the absorption profile during the time span of our observations. [...] The second component has XD/XH abundances that are 100 times larger than the primordial D/H ratio, a deepening of the absorption by a factor of two within a few months, and a rich chemical composition, with relative enhancements of N2H+, CH3OH, SO2, and complex organic molecules. We therefore speculate that this component is associated with the analog of a Galactic dark cloud, while the first component is likely more diffuse. Our search for the 7LiH (1--0) line was unsuccessful and we derive an upper limit 7LiH/H2 = 4 x 10^-13 (3sigma) in the z=0.89 absorber toward PKS1830-211. Besides, with ALMA archival data, we could not confirm the previous tentative detections of this line in the z=0.68 absorber toward B0218+357; we derive an upper limit 7LiH/H2 = 5 x 10^-11 (3sigma), although this is less constraining than our limit toward PKS1830-211. We conclude that, as in the Milky Way, only a tiny fraction of lithium nuclei are possibly bound in LiH in these absorbers at intermediate redshift., Comment: Accepted for publication in A&A
- Published
- 2020
- Full Text
- View/download PDF
87. Molecular gas and star formation activity in LIRGs in clusters at intermediate redshifts
- Author
-
Castignani, G., Jablonka, P., Combes, F., Haines, C. P., Rawle, T., Jauzac, M., Egami, E., Krips, M., Spérone-Longin, D., Arnaud, M., García-Burillo, S., Schinnerer, E., and Bigiel, F.
- Subjects
Astrophysics - Astrophysics of Galaxies ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We investigate the role of dense Mpc-scale environments in processing molecular gas of cluster galaxies as they fall into the cluster cores. We consider $\sim20$ luminous infrared galaxies (LIRGs) in intermediate-$z$ clusters, from the Hershel Lensing Survey and the Local Cluster Substructure Survey. They include MACS J0717.5+3745 at $z=0.546$ and Abell 697, 963, 1763, and 2219 at $z=0.2-0.3$. We have performed far infrared to ultraviolet spectral energy distribution modeling of the LIRGs, which span cluster-centric distances within $r/r_{200}\simeq0.2-1.6$. We have observed the LIRGs in CO(1$\rightarrow$0) or CO(2$\rightarrow$1) with the Plateau de Bure interferometer and its successor NOEMA, as part of five observational programs carried out between 2012 and 2017. We have compared the molecular gas to stellar mass ratio $M(H_2)/M_\star$, star formation rate (SFR), and depletion time ($\tau_{\rm dep}$) of the LIRGs with those of a compilation of cluster and field star forming galaxies. The targeted LIRGs have SFR, $M(H_2)/M_\star$, and $\tau_{\rm dep}$ that are consistent with those of both main sequence (MS) field galaxies and star forming galaxies from the comparison sample. However we find that the depletion time, normalized to the MS value, increases with increasing $r/r_{200}$, with a significance of $2.8\sigma$, which is ultimately due to a deficit of cluster core LIRGs with $\tau_{\rm dep}\gtrsim\tau_{\rm dep,MS}$. We suggest that a rapid exhaustion of the molecular gas reservoirs occurs in the cluster LIRGs and is effective in suppressing their star formation. This mechanism may explain the exponential decrease of the fraction of cluster LIRGs with cosmic time. The compression of the gas in LIRGs, possibly induced by intra-cluster medium shocks, may be responsible for the short depletion timescales, observed in a large fraction of cluster core LIRGs., Comment: 26 pages, 10 figures, 5 tables, A&A in press
- Published
- 2020
- Full Text
- View/download PDF
88. Environmental processing in cluster core galaxies at z=1.7
- Author
-
Castignani, G., Combes, F., and Salomé, P.
- Subjects
Astrophysics - Astrophysics of Galaxies ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Today, the brightest cluster galaxies (BCGs) are passive and very massive galaxies at the center of their clusters, and they still accrete mass through swallowing companions and gas from cooling flows. However their formation history is not well known. We report CO(4$\rightarrow$3) and continuum map observations of the SpARCS1049+56 BCG at $z=1.709$, one of the most distant known BCGs. Our observations yield $M_{{\rm H}_2}<1.1\times10^{10}M_\odot$ for the BCG; while in CO(4$\rightarrow$3), we detect two gas-rich companions at the northeast and southeast of the BCG, within 20 kpc, with ${L^\prime_{\rm CO(4\rightarrow3)}=(5.8\pm0.6)\times10^{9}}$ K km s$^{-1}$ pc$^2$ and $(7.4\pm0.7)\times10^{9}$ K km s$^{-1}$ pc$^2$, respectively. The northern companion is associated with a pair of merging cluster galaxies, while the southern one shows a southern tail in CO(4$\rightarrow$3), which was also detected in continuum, and we suggest it to be the most distant jellyfish galaxy for which ram pressure stripping is effectively able to strip off its dense molecular gas. This study probes the presence of rare gas-rich systems in the very central region of a distant cluster core, which will potentially merge into the BCG itself. Currently, we may thus be seeing the reversal of the star formation versus density relation at play in the distant universe. This is the first time the assembly of high-$z$ progenitors of our local BCGs can be studied in such great detail., Comment: 6 pages, 3 figures, accepted for publication in A&A Letters
- Published
- 2020
- Full Text
- View/download PDF
89. Molecular gas in distant brightest cluster galaxies
- Author
-
Castignani, G., Combes, F., Salomé, P., and Freundlich, J.
- Subjects
Astrophysics - Astrophysics of Galaxies ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
The stellar mass assembly of brightest cluster galaxies (BCGs) is still debated. We have observed in CO with the IRAM-30m two star forming BCGs belonging to SpARCS clusters, 3C 244.1 ($z=0.4$) and SDSS J161112.65+550823.5 ($z=0.9$), and compared their molecular gas and star formation properties with those of a compilation of $\sim100$ distant cluster galaxies, including nine additional distant BCGs at ${z\sim0.4-3.5}$. We have set robust upper limits of $M_{{\rm H}_2}<1.0\times10^{10}~M_\odot$ and $<2.8\times10^{10}~M_\odot$ to their molecular gas content, respectively, as well as to the molecular gas to stellar mass ratio $M({\rm H}_2)/M_\star\lesssim0.2$ and depletion time $\tau_{\rm dep}\lesssim40$ Myr of the two targeted BCGs. They are thus among the distant cluster galaxies with the lowest gas fractions and shortest depletion times. The majority, $64\%\pm15\%$ and $73\%\pm18\%$, of the 11 BCGs with observations in CO have lower $M({\rm H}_2)/M_\star$ and $\tau_{\rm dep}$, respectively, than those estimated for main sequence galaxies. Statistical analysis tentatively suggests that the values of $M({\rm H}_2)/M_\star$ and $\tau_{\rm dep}$ for the 11 BCGs deviates, with a significance of $\sim2\sigma$, from those of the comparison sample of cluster galaxies. A morphological analysis for a subsample of seven BCGs with archival HST observations reveals that $71\%\pm17\%$ of the BCGs are compact or show star-forming substructures/components. Our results suggest a scenario where distant star forming BCGs assemble a significant fraction $\sim16\%$ of their stellar mass in the relatively short timescale $\tau_{\rm dep}$, while environmental mechanisms might prevent the replenishment of gas feeding the star formation. We speculate that compact components favor the rapid exhaustion of molecular gas and help to quench the BCGs. Distant star forming BCGs are excellent targets for ALMA and JWST., Comment: 18 pages, 4 figures, accepted for publication in A&A
- Published
- 2019
- Full Text
- View/download PDF
90. Molecular gas and star formation in the Milky Way
- Author
-
Combes F.
- Subjects
Physics ,QC1-999 - Abstract
The dense molecular gas is the ideal tracer of the spiral structure in the Milky Way, and should be used intensively to solve the puzzle of its structure. In spite of our position inside the plane, we can hope to disentangle the structures, with position-velocity diagrams, in addition to (l − b). I summarize the state of the art simulations of gas flows in the MW, and describe what can be done to improve the models, taking into account the star formation, in view of what is already done in external galaxies, with a more favorable viewing angle.
- Published
- 2012
- Full Text
- View/download PDF
91. A CO molecular gas wind 340 pc away from the Seyfert 2 nucleus in ESO 420-G13 probes an elusive radio jet
- Author
-
Fernández-Ontiveros, J. A., Dasyra, K. M., Hatziminaoglou, E., Malkan, M. A., Pereira-Santaella, M., Papachristou, M., Spinoglio, L., Combes, F., Aalto, S., Nagar, N., Imanishi, M., Andreani, P., Ricci, C., and Slater, R.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
A prominent jet-driven outflow of CO(2-1) molecular gas is found along the kinematic minor axis of the Seyfert 2 galaxy ESO 420-G13, at a distance of $340-600\, \rm{pc}$ from the nucleus. The wind morphology resembles a characteristic funnel shape, formed by a highly collimated filamentary emission at the base, likely tracing the jet propagation through a tenuous medium, until a bifurcation point at $440\, \rm{pc}$ where the jet hits a dense molecular core and shatters, dispersing the molecular gas into several clumps and filaments within the expansion cone. We also trace the jet in ionised gas within the inner $\lesssim 340\, \rm{pc}$ using the [NeII]$_{\rm 12.8 \mu m}$ line emission, where the molecular gas follows a circular rotation pattern. The wind outflow carries a mass of $\sim 8 \times 10^6\, \rm{M_\odot}$ at an average wind projected speed of $\sim 160\, \rm{km\,s^{-1}}$, which implies a mass outflow rate of $\sim 14\, \rm{M_\odot\,yr^{-1}}$. Based on the structure of the outflow and the budget of energy and momentum, we discard radiation pressure from the active nucleus, star formation, and supernovae as possible launching mechanisms. ESO 420-G13 is the second case after NGC 1377 where the presence of a previously unknown jet is revealed due to its interaction with the interstellar medium, suggesting that unknown jets in feeble radio nuclei might be more common than expected. Two possible jet-cloud configurations are discussed to explain the presence of an outflow at such distance from the AGN. The outflowing gas will likely not escape, thus a delay in the star formation rather than quenching is expected from this interaction, while the feedback effect would be confined within the central few hundred parsecs of the galaxy., Comment: 12 pages, 8 figures. Accepted for publication in A&A
- Published
- 2019
- Full Text
- View/download PDF
92. Towards sub-kpc scale kinematics of molecular and ionized gas of star-forming galaxies at $z\sim1$
- Author
-
Girard, M., Dessauges-Zavadsky, M., Combes, F., Chisholm, J., Patricio, V., Richard, J., and Schaerer, D.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We compare the molecular and ionized gas kinematics of two strongly lensed galaxies at $z\sim1$ based on observations from ALMA and MUSE. We derive the CO and [OII] rotation curves and dispersion profiles of these two galaxies. We find a difference between the observed molecular and ionized gas rotation curves for one of the galaxies, the Cosmic Snake, for which we obtain a spatial resolution of few hundred parsecs along the major axis. The rotation curve of the molecular gas is steeper than the rotation curve of the ionized gas. In the second galaxy, A521, the molecular and ionized gas rotation curves are consistent, but the spatial resolution is only of few kpc on the major axis. Using simulations, we investigate the effect of the thickness of the gas disk and effective radius on the observed rotation curves and find that a more extended and thicker disk smooths the curve. We also find that the presence of a strongly inclined thick disk (>1 kpc) can smooth the rotation curve because it degrades the spatial resolution along the line of sight. By building a model using a stellar disk and two gas disks, we reproduce the rotation curves of the Cosmic Snake with a molecular gas disk that is more massive and more radially and vertically concentrated than the ionized gas disk. Finally, we also obtain an intrinsic velocity dispersion in the Cosmic Snake of 18.5+-7 km/s and 19.5+-6 km/s for the molecular and ionized gas, respectively, which is consistent with a molecular disk with a smaller and thinner disk. For A521, the intrinsic velocity dispersion values are 11+-8 km/s and 54+-11 km/s, with a higher value for the ionized gas. This could indicate that the ionized gas disk is thicker and more turbulent in this galaxy. These results highlight the different spatial distribution of the molecular and ionized gas disks at $z\sim1$ and suggest the presence of thick ionized gas disks at this epoch., Comment: 11 pages, 8 figures, accepted for publication in A&A
- Published
- 2019
- Full Text
- View/download PDF
93. Probing the merger history of red early-type galaxies with their faint stellar substructures
- Author
-
Mancillas, B., Duc, P. -A., Combes, F., Bournaud, F., Emsellem, E., Martig, M., and Michel-Dansac, L.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
Several deep observations such as those carried out at the Canada-France-Hawaii Telescope (CFHT) have revealed prominent Low Surface Brightness (LSB) fine structures that change the apparent morphology of galaxies. Previous photometry surveys have developed observational techniques which exploit the diffuse light detected in the external regions of galaxies. In these studies the outer perturbations have been identified and classified like tidal tails, stellar streams, and shells. These structures are tracers of interacting and merging events and they keep a memory of the mass assembly of galaxies. Cosmological numerical simulations are needed to estimate their visibility time-scale (among other properties) in order to reconstruct the past merger history of galaxies. In the present work, we analyze a hydrodynamical cosmological simulation to build a comprehensive interpretation of the properties of fine structures. We make a census of several types of LSB fine structures by visual inspection of individual snapshots at various time. We reconstruct the evolution of the number of fine structures detected around an early-type galaxy and we compare with the merger history of the galaxy. We find that most of fine structures are associated with major and intermediate mass merger events. Their survival time scale ranges between 0.7 and 4 Gyr. Shells and streams remain visible for a longer time than tidal tails. These estimates of survival times provide clues to interpret the shape and frequency of fine structures observed in deep images in terms of mass assembly. We find that the detectability of stellar streams is the most sensitive to the surface brightness limit. We see 2-3 times more streams with a surface brightness cut of 33 mag arcsec$^{-2}$ than with 29 mag arcsec$^{-2}$. The detection of shells display a strong dependence on the projection angle., Comment: 16 pages, 14 figures, accepted in A&A (v2 after language editing)
- Published
- 2019
- Full Text
- View/download PDF
94. Dense gas formation and destruction in a simulated Perseus-like galaxy cluster with spin-driven black hole feedback
- Author
-
Beckmann, R. S., Dubois, Y., Guillard, P., Salome, P., Olivares, V., Polles, F., Cadiou, C., Combes, F., Hamer, S., Lehnert, M. D., and Forets, G. Pineau des
- Subjects
Astrophysics - Astrophysics of Galaxies ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
Extended filamentary H$\alpha$ emission nebulae are a striking feature of nearby galaxy clusters but the formation mechanism of the filaments, and the processes which shape their morphology remain unclear. We conduct an investigation into the formation, evolution and destruction of dense gas in the center of a simulated, Perseus-like, cluster under the influence of a spin-driven jet. We particularly study the role played by condensation of dense gas from the diffuse intracluster medium, and the impact of direct uplifting of existing dense gas by the jets, in determining the spatial distribution and kinematics of the dense gas. We present a hydrodynamical simulation of an idealised Perseus-like cluster using the adaptive mesh refinement code {\sc ramses}. Our simulation includes a supermassive black hole (SMBH) that self-consistently tracks its spin evolution via its local accretion, and in turn drives a large-scale jet whose direction is based on the black hole's spin evolution. We show that the formation and destruction of dense gas is closely linked to the SMBH's feedback cycle, and that its morphology is highly variable throughout the simulation. While extended filamentary structures readily condense from the hot intra-cluster medium, they are easily shattered into an overly clumpy distribution of gas during their interaction with the jet driven outflows. Condensation occurs predominantly onto infalling gas located 5 - 15 kpc from the center during quiescent phases of the central AGN, when the local ratio of the cooling time to free fall time falls below 20, i.e. when $t_{\rm cool}/t_{\rm ff} < 20$. We find evidence for both condensation and uplifting of dense gas, but caution that purely hydrodynamical simulations struggle to effectively regulate the cluster cooling cycle and produce overly clumpy distributions of dense gas morphologies, compared to observation., Comment: 18 pages, 17 Figures. Accepted for publication in A&A
- Published
- 2019
- Full Text
- View/download PDF
95. ALMA images the many faces of the NGC1068 torus and its surroundings
- Author
-
Garcia-Burillo, S., Combes, F., Almeida, C. Ramos, Usero, A., Alonso-Herrero, A., Hunt, L. K., Rouan, D., Aalto, S., Querejeta, M., Viti, S., van der Werf, P. P., Vives-Arias, H., Fuente, A., Colina, L., Martin-Pintado, J., Henkel, C., Martin, S., Krips, M., Gratadour, D., Neri, R., and Tacconi, L. J.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We investigate the fueling and the feedback of nuclear activity in the Seyfert 2 galaxy NGC1068, by studying the distribution and kinematics of molecular gas in the torus and its connections. We use ALMA to image the emission of a set of molecular gas tracers in the circumnuclear disk (CND) and the torus of the galaxy using the CO(2-1), CO(3-2) and HCO+(4-3) lines with spatial resolutions ~0.03"-0.09"(2-6pc). ALMA resolves the CND as an asymmetric ringed disk of D~400pc-size and mass of ~1.4x10^8 Msun. The inner edge of the ring is associated with edge-brightened arcs of NIR polarized emission identified with the working surface of the AGN ionized wind. ALMA proves the existence of a molecular torus of M_torus ~ 3x10^5Msun, which extends over a large range of spatial scales D=10-30pc around the central engine. The new observations evidence the density radial stratification of the torus: the HCO+(4-3) torus, with a full size D=11pc, is a factor of 2-3 smaller than its CO(2-1) and CO(3-2) counterparts, which have full-sizes D=26pc and D=28pc, respectively. The torus is connected to the CND through a network of gas streamers. The kinematics of molecular gas show strong departures from circular motions in the torus, the gas streamers, and the CND. These velocity distortions are interconnected and are part of a 3D outflow that reflects the effects of AGN feedback on the kinematics of molecular gas across a wide range of spatial scales. We conclude that a wide-angle AGN wind launched from the accretion disk is impacting a sizeable fraction of the gas inside the torus (~0.4-0.6 x M_torus). However, a large gas reservoir (~1.2-1.8 x 10^5Msun) close to the equatorial plane of the torus remains unaffected by the AGN wind and can continue fueling the AGN for ~1-4Myr. AGN fueling seems nevertheless thwarted on intermediate scales (15pc < r < 50pc)., Comment: Revised version accepted by A&A on October 13th 2019, 28 pages, 30 figures
- Published
- 2019
- Full Text
- View/download PDF
96. SIGNALS: I. Survey Description
- Author
-
Rousseau-Nepton, L., Martin, R. P., Robert, C., Drissen, L., Amram, P., Prunet, S., Martin, T., Moumen, I., Adamo, A., Alarie, A., Barmby, P., Boselli, A., Bresolin, F., Bureau, M., Chemin, L., Fernandes, R. C., Combes, F., Crowder, C., Della Bruna, L., Egusa, F., Epinat, B., Ksoll, V. F., Girard, M., Llanos, V. Gómez, Gouliermis, D., Grasha, K., Higgs, C., Hlavacek-Larrondo, J., Ho, I. -T., Iglesias-Páramo, J., Joncas, G., Kam, Z. S., Karera, P., Kennicutt, R. C., Klessen, R. S., Lianou, S., Liu, L., Liu, Q., de Amorim, A. Luiz, Lyman, J. D., Martel, H., Mazzilli-Ciraulo, B., McLeod, A. F., Melchior, A-L., Millan, I., Mollá, M., Momose, R., Morisset, C., Pan, H. -A., Pati, A. K., Pellerin, A., Pellegrini, E., Pérez, I., Petric, A., Plana, H., Rahner, D., Lara, T. Ruiz, Sánchez-Menguiano, L., Spekkens, K., Stasińska, G., Takamiya, M., Asari, N. Vale, and Vílchez, J. M.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
SIGNALS, the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey, is a large observing program designed to investigate massive star formation and HII regions in a sample of local extended galaxies. The program will use the imaging Fourier transform spectrograph SITELLE at the Canada-France-Hawaii Telescope. Over 355 hours (54.7 nights) have been allocated beginning in fall 2018 for eight consecutive semesters. Once completed, SIGNALS will provide a statistically reliable laboratory to investigate massive star formation, including over 50 000 resolved HII regions : the largest, most complete, and homogeneous database of spectroscopically and spatially resolved extragalactic HII regions ever assembled. For each field observed, three datacubes covering the spectral bands of the filters SN1 (363 -386 nm), SN2 (482 - 513 nm), and SN3 (647 - 685 nm) are gathered. The spectral resolution selected for each spectral band is 1000, 1000, and 5000, respectively. As defined, the project sample will facilitate the study of small-scale nebular physics and many other phenomena linked to star formation at a mean spatial resolution of 20 pc. This survey also has considerable legacy value for additional topics including planetary nebulae, diffuse ionized gas, andsupernova remnants. The purpose of this paper is to present a general outlook of the survey, notably the observing strategy, galaxy sample, and science requirements., Comment: 19 pages, 14 figures, submitted to MNRAS
- Published
- 2019
- Full Text
- View/download PDF
97. Complex molecular gas kinematics in the inner 5 kpc of 4C12.50 as seen by ALMA
- Author
-
Fotopoulou, C. M., Dasyra, K. M., Combes, F., Salomé, P., and Papachristou, M.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
The nearby system 4C12.50, also known as IRAS 13451+1217 and PKS 1345+12, is a merger of gas-rich galaxies with infrared and radio activity. It has a perturbed interstellar medium (ISM) and a dense configuration of gas and dust around the nucleus. The radio emission at small ($\sim$100 pc) and large ($\sim$100 kpc) scales, as well as the large X-ray cavity in which the system is embedded, are indicative of a jet that could have affected the ISM. We carried out observations of the CO(1-0), (3-2), and (4-3) lines with the Atacama Large Millimeter Array (ALMA) to determine basic properties (i.e., extent, mass, and excitation) of the cold molecular gas in this system, including its already-known wind. The CO emission reveals the presence of gaseous streams related to the merger, which result in a small ($\sim$4kpc-wide) disk around the western nucleus. The disk reaches a rotational velocity of 200 $kms^{-1}$ , and has a mass of 3.8($\pm$0.4)$\times$10${^9}M_{\odot}$. It is truncated at a gaseous ridge north of the nucleus that is bright in [O III]. Regions with high-velocity CO emission are seen at signal-to-noise ratios of between 3 and 5 along filaments that radially extend from the nucleus to the ridge and that are bright in [O III] and stellar emission. A tentative wind detection is also reported in the nucleus and in the disk. The molecular gas speed could be as high as 2200 $kms^{-1}$ and the total wind mass could be as high as 1.5($\pm$0.1)$\times$10$^9M_{\odot}$. Energetically, it is possible that the jet, assisted by the radiation pressure of the active nucleus or the stars, accelerated clouds inside an expanding bubble.
- Published
- 2019
- Full Text
- View/download PDF
98. Constraining cold accretion onto supermassive black holes: molecular gas in the cores of eight brightest cluster galaxies revealed by joint CO and CN absorption
- Author
-
Rose, Tom, Edge, A. C., Combes, F., Gaspari, M., Hamer, S., Nesvadba, N., Peck, A. B., Sarazin, C., Tremblay, G. R., Baum, S. A., Bremer, M. N., McNamara, B. R., O'Dea, C., Oonk, J. B. R., Russell, H., Salomé, P., Donahue, M., Fabian, A. C., Ferland, G., Mittal, R., and Vantyghem, A.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
To advance our understanding of the fuelling and feedback processes which power the Universe's most massive black holes, we require a significant increase in our knowledge of the molecular gas which exists in their immediate surroundings. However, the behaviour of this gas is poorly understood due to the difficulties associated with observing it directly. We report on a survey of 18 brightest cluster galaxies lying in cool cores, from which we detect molecular gas in the core regions of eight via carbon monoxide (CO), cyanide (CN) and silicon monoxide (SiO) absorption lines. These absorption lines are produced by cold molecular gas clouds which lie along the line of sight to the bright continuum sources at the galaxy centres. As such, they can be used to determine many properties of the molecular gas which may go on to fuel supermassive black hole accretion and AGN feedback mechanisms. The absorption regions detected have velocities ranging from -45 to 283 km s$^{-1}$ relative to the systemic velocity of the galaxy, and have a bias for motion towards the host supermassive black hole. We find that the CN N = 0 - 1 absorption lines are typically 10 times stronger than those of CO J = 0 - 1. This is due to the higher electric dipole moment of the CN molecule, which enhances its absorption strength. In terms of molecular number density CO remains the more prevalent molecule with a ratio of CO/CN $\sim 10$, similar to that of nearby galaxies. Comparison of CO, CN and HI observations for these systems shows many different combinations of these absorption lines being detected., Comment: Accepted for publication in MNRAS
- Published
- 2019
- Full Text
- View/download PDF
99. A nuclear molecular outflow in the Seyfert galaxy NGC3227
- Author
-
Alonso-Herrero, A., Garcia-Burillo, S., Pereira-Santaella, M., Davies, R. I., Combes, F., Vestergaard, M., Raimundo, S. I., Bunker, A., Diaz-Santos, T., Gandhi, P., Garcia-Bernete, I., Hicks, E. K. S., Hönig, S. F., Hunt, L. K., Imanishi, M., Izumi, T., Levenson, N. A., Maciejewski, W., Packham, C., Almeida, C. Ramos, Ricci, C., Rigopoulou, D., Roche, P. F., Rosario, D., Schartmann, M., Usero, A., and Ward, M. J.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
We present ALMA observations of the CO(2-1) and CO(3-2) molecular gas transitions and associated (sub)-mm continua of the nearby Seyfert 1.5 galaxy NGC3227 with angular resolutions 0.085-0.21" (7-15pc). On large scales the cold molecular gas shows circular motions as well as streaming motions on scales of a few hundred parsecs associated with a large scale bar. We fitted the nuclear ALMA 1.3mm emission with an unresolved component and an extended component. The 850$\mu$m emission shows at least two extended components, one along the major axis of the nuclear disk and the other along the axis of the ionization cone. The molecular gas in the central region (1" ~73pc) shows several CO clumps with complex kinematics which appears to be dominated by non-circular motions. While we cannot demonstrate conclusively the presence of a warped nuclear disk, we also detected non-circular motions along the kinematic minor axis. They reach line-of-sight velocities of v-vsys =150-200km/s. Assuming that the radial motions are in the plane of the galaxy, then we interpret them as a nuclear molecular outflow due to molecular gas in the host galaxy being entrained by the AGN wind. We derive molecular outflow rates of $5\,M_\odot\,{\rm yr}^{-1}$ and $0.6\,M_\odot\,{\rm yr}^{-1}$ at projected distances of up to 30pc to the northeast and southwest of the AGN, respectively. At the AGN location we estimate a mass in molecular gas of $5\times 10^{5}\,M_\odot$ and an average column density $N({\rm H}_2) = 2-3\times 10^{23}\,{\rm cm}^{-2}$ in the inner 15pc. The nuclear molecular gas and sub-mm continuum emission of NGC3227 do not resemble the classical compact torus. Rather, these emissions extend for several tens of parsecs and appear connected with the circumnuclear ring in the host galaxy disk, as found in other local AGN. (Abridged), Comment: Accepted for publication in Astronomy and Astrophysics, 17 pages, 12 figures
- Published
- 2019
- Full Text
- View/download PDF
100. The Close AGN Reference Survey (CARS). Discovery of a global [CII] 158 $\mu$m line excess in AGN HE1353-1917
- Author
-
Smirnova-Pinchukova, I., Husemann, B., Busch, G., Appleton, P., Bethermin, M., Combes, F., Croom, S., Davis, T. A., Fischer, C., Gaspari, M., Groves, B., Klein, R., O'Dea, C. P., Pérez-Torres, M., Scharwächter, J., Singha, M., Tremblay, G. R., and Urrutia, T.
- Subjects
Astrophysics - Astrophysics of Galaxies - Abstract
The [CII]158$\mu$m line is one of the strongest far-infrared (FIR) lines and an important coolant in the interstellar medium of galaxies that is accessible out to high redshifts. The excitation of [CII] is complex and can best be studied in detail at low redshifts. Here we report the discovery of the highest global [CII] excess with respect to the FIR luminosity in the nearby AGN host galaxy HE1353-1917. This galaxy is exceptional among a sample of five targets because the AGN ionization cone and radio jet directly intercept the cold galactic disk. As a consequence, a massive multiphase gas outflow on kiloparsec scales is embedded in an extended narrow-line region. Because HE1353-1917 is distinguished by these special properties from our four bright AGN, we propose that a global [CII] excess in AGN host galaxies could be a direct signature of a multiphase AGN-driven outflow with a high mass-loading factor., Comment: 7 pages, 6 figures, accepted for publication in A&A Letters
- Published
- 2019
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.