@article {2015A\&A...574A..65B, title = {{Molecular gas and nuclear activity in early-type galaxies: any link with radio loudness?}}, journal = {Astronomy and Astrophysics}, volume = {574}, year = {2015}, month = {feb}, pages = {A65}, abstract = {
Aims: We want to study the amount of molecular gas in a sample of nearby early-type galaxies (ETGs) that host low-luminosity active galactic nuclei (AGN). We look for possible differences between the radio-loud (RL) and radio-quiet (RQ) AGN.
Methods: We observed the CO(1-0) and CO(2-1) spectral lines with the IRAM 30 m and NRO 45 m telescopes for eight galaxies. They belong to a large sample of 37 local ETGs that host both RQ and RL AGN. We gather data from the literature for the entire sample.
Results: We report the new detection of CO(1-0) emission in four galaxies (UGC 0968, UGC 5617, UGC 6946, and UGC 8355) and CO(2-1) emission in two of them (UGC 0968 and UGC 5617). The CO(2-1)/CO(1-0) ratio in these sources is \~{} 0.7 {\plusmn} 0.2. Considering both the new observations and the literature, the detection rate of CO in our sample is 55{\plusmn} 9\%, with no statistically significant difference between the hosts of RL and RQ AGNs. For all the detected galaxies we converted the CO luminosities into the molecular masses, M$_{H2}$, which range from 10$^{6.5}$ to 10$^{8.5}$ M$_{\&sun;}$, without any statistically significant differences between RL and RQ galaxies. This suggests that the amount of molecular gas does not likely set the radio loudness of the AGN. Furthermore, despite the low statistical significance, the presence of a weak trend between the H$_{2}$ mass with various tracers of nuclear activity (mainly [O III] emission line nuclear power) cannot be excluded. Based on observations carried out with the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).}, keywords = {cD, galaxies: active, galaxies: elliptical and lenticular, galaxies: ISM, galaxies: nuclei, ISM: molecules}, doi = {10.1051/0004-6361/201425131}, url = {http://adsabs.harvard.edu/abs/2015A\%26A...574A..65B}, author = {Baldi, R.~D. and Giroletti, M. and Capetti, A. and Giovannini, G. and Casasola, V. and M. A. P{\'e}rez-Torres and Kuno, N.} } @article {2011A\&A...528A..30C, title = {{Molecules as tracers of galaxy evolution: an EMIR survey. I. Presentation of the data and first results}}, journal = {Astronomy and Astrophysics}, volume = {528}, year = {2011}, month = {apr}, pages = {A30}, abstract = {
Aims: We investigate the molecular gas properties of a sample of 23 galaxies in order to find and test chemical signatures of galaxy evolution and to compare them to IR evolutionary tracers.
Methods: Observation at 3 mm wavelengths were obtained with the EMIR broadband receiver, mounted on the IRAM 30 m telescope on Pico Veleta, Spain. We compare the emission of the main molecular species with existing models of chemical evolution by means of line intensity ratios diagrams and principal component analysis.
Results: We detect molecular emission in 19 galaxies in two 8 GHz-wide bands centred at 88 and 112 GHz. The main detected molecules are CO, $^{13}$CO, HCN, HNC, HCO$^{+}$, CN, and C$_{2}$H. We also detect HC$_{3}$N J = 10-9 in the galaxies IRAS 17208, IC 860, NGC 4418, NGC 7771, and NGC 1068. The only HC$_{3}$N detections are in objects with HCO$^{+}$/HCN {\l}t} 1. Galaxies with the highest HC$_{3}$N/HCN ratios have warm IRAS colours (60/100 {$μ$}m {\gt} 0.8). The brightest HC$_{3}$N emission is found in IC 860, where we also detect the molecule in its vibrationally excited state. We find low HNC/HCN line ratios ({\l}t}0.5), that cannot be explained by existing PDR or XDR chemical models. The intensities of HCO+ and HNC appear anti-correlated. No correlation is found between the HNC/HCN line ratio and dust temperature. All HNC-bright objects are either luminous IR galaxies (LIRG) or Seyferts. Galaxies with bright polycyclic aromatic hydrocarbons (PAH) emission show low HNC/HCO$^{+}$ ratios. The CO/$^{13}$CO ratio is positively correlated with the dust temperature and is generally higher than in our galaxy. The emission of CN and C$^{18}$O is correlated.
Conclusions: Bright HC$_{3}$N emission in HCO$^{+}$-faint objects may imply that these are not dominated by X-ray chemistry. Thus the HCN/HCO$^{+}$ line ratio is not, by itself, a reliable tracer of XDRs. Bright HC$_{3}$N and faint HCO$^{+}$ could be signatures of embedded star-formation, instead of AGN activity. Mechanical heating caused by supernova explosions may be responsible for the low HNC/HCN and high HCO$^{+}$/HCN ratios in some starbursts. We cannot exclude, however, that the discussed trends are largely caused by optical depth effects or excitation. Chemical models alone cannot explain all properties of the observed molecular emission. Better constraints to the gas spacial distribution and excitation are needed to distinguish abundance and excitation effects. Appendices are only available in electronic form http://www.aanda.org}, keywords = {evolution, galaxies: active, galaxies: evolution, galaxies: ISM, ISM: molecules}, doi = {10.1051/0004-6361/201015628}, url = {http://adsabs.harvard.edu/abs/2011A\%26A...528A..30C}, author = {F. Costagliola and Aalto, S. and M. Rodr{\'\i}guez and Muller, S. and Spoon, H.~W.~W. and Mart{\'\i}n, S. and M. A. P{\'e}rez-Torres and Alberdi, A. and Lindberg, J.~E. and Batejat, F. and J{\"u}tte, E. and van der Werf, P. and Lahuis, F.} } @article {2010MNRAS.408L...1H, title = {{Integral-field spectroscopy of type II QSOs at z = 0.3-0.4}}, journal = {Monthly Notices of the Royal Astronomical Society}, volume = {408}, year = {2010}, month = {oct}, pages = {L1-L5}, abstract = {We present and analyse integral-field observations of six type II QSOs with z = 0.3-0.4, selected from the Sloan Digital Sky Survey (SDSS). Two of our sample are found to be surrounded by a nebula of warm ionized gas, with the largest nebula extending across 8 arcsec (40 kpc). Some regions of the extended nebulae show kinematics that are consistent with gravitational motion, while other regions show relatively perturbed kinematics: velocity shifts and linewidths too large to be readily explained by gravitational motion. We propose that a \~{}20 {\times} 20 kpc outflow is present in one of the galaxies. Possible mechanisms for triggering the outflow are discussed. In this object, we also find evidence for ionization both by shocks and by the radiation field of the AGN.}, keywords = {galaxies: active, galaxies: high-redshift, galaxies: ISM}, doi = {10.1111/j.1745-3933.2010.00906.x}, url = {http://adsabs.harvard.edu/abs/2010MNRAS.408L...1H}, author = {Humphrey, A. and Villar-Mart{\'\i}n, M. and S{\'a}nchez, S.~F. and Mart{\'\i}nez-Sansigre, A. and Delgado, R.~G. and P{\'e}rez, E. and Tadhunter, C. and M. A. P{\'e}rez-Torres} } @article {2010MNRAS.407L...6V, title = {{VLT and GTC observations of SDSS J0123+00: a type 2 quasar triggered in a galaxy encounter}}, journal = {Monthly Notices of the Royal Astronomical Society}, volume = {407}, year = {2010}, month = {sep}, pages = {L6-L10}, abstract = {We present long-slit spectroscopy, continuum and [OIII] {${\l}ambda$}5007 imaging data obtained with the Very Large Telescope and the Gran Telescopio Canarias of the type 2 quasar SDSS J0123+00 at z = 0.399. The quasar lies in a complex, gas-rich environment. It appears to be physically connected by a tidal bridge to another galaxy at a projected distance of \~{}100kpc, which suggests this is an interacting system. Ionized gas is detected to a distance of at least \~{}133kpc from the nucleus. The nebula has a total extension of \~{}180kpc. This is one of the largest ionized nebulae ever detected associated with an active galaxy. Based on the environmental properties, we propose that the origin of the nebula is tidal debris from a galactic encounter, which could as well be the triggering mechanism of the nuclear activity. SDSS J0123+00 demonstrates that giant, luminous ionized nebulae can exist associated with type 2 quasars of low radio luminosities, contrary to expectations based on type 1 quasar studies. Based on observations carried out at the European Southern Observatory (Paranal, Chile) with FORS2 on VLT-UT1 [programme 69.A-0123(A)] and at the Observatory Roque de los Muchachos (La Palma, Spain) with OSIRIS on GTC (programme GTC27-09A). E-mail: montse@iaa.es}, keywords = {galaxies: ISM, quasars individual: SDSS J012341.47+004435.9, quasars: emission lines}, doi = {10.1111/j.1745-3933.2010.00890.x}, url = {http://adsabs.harvard.edu/abs/2010MNRAS.407L...6V}, author = {Villar-Mart{\'\i}n, M. and Tadhunter, C. and P{\'e}rez, E. and Humphrey, A. and Mart{\'\i}nez-Sansigre, A. and Delgado, R.~G. and M. A. P{\'e}rez-Torres} }