Detection of HCN, HCO+, and HNC in the Mrk 231 molecular outflow. Dense molecular gas in the AGN wind

By S. Aalto, S. García-Burillo, Sebastien Muller, J. Winters, P. Werf, C. Henkel, F. Costagliola, R. Neri. 2011

162 citations recorded by the source corpus.

We obtained high-resolution (1.''55 × 1.''28) observations of HCN, HCO+, HNC 1-0 and HC3N 10-9 of the ultraluminous galaxy (ULIRG) Mrk 231 with the IRAM Plateau de Bure Interferometer. Results: We detect luminous emission from HCN, HCO+ and HNC 1-0 in the QSO ULIRG Mrk 231. All three lines show broad line wings - which are particularly prominent for HCN. Velocities are found to be similar ( ≈ ± 750 km s-1) to those found for CO 1-0. This is the first time bright HCN, HCO+ and HNC emission has been detected in a large-scale galactic outflow. We find that both the blue- and red-shifted line wings are spatially extended by at least 0.''75 (>700 pc) in a north-south direction. The line wings are brighter (relative to the line center intensity) in HCN than in CO 1-0 and line ratios suggest that the molecular outflow consists of dense (n > 104 cm-3) and clumpy gas with a high HCN abundance X(HCN) > 10-8. These properties are consistent with the molecular gas being compressed and fragmented by shocks in the outflow. Alternatively, HCN is instead pumped by mid-IR continuum, but we propose that this effect is not strong for the spatially extended outflowing gas. In addition, we find that the rotation of the main disk, in east-west direction, is also evident in the HCN, HCO+ and HNC line emission. An unexpectedly bright HC3N 10-9 line is detected inside the central 400 pc of Mrk 231. This HC3N emission may emerge from a shielded, dust-enshrouded region within the inner 40-50 pc where the gas is heated to high temperatures (200-300 K) by the AGN.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/9565c7fcf994290b71545816713766e58635c8bb

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. D. M. Alexander
2. P. Hopkins
3. H. Netzer
4. R. Maiolino
5. L. Hernquist
6. R. Genzel
7. L. Tacconi
8. Sylvain Veilleux

Citations in the corpus

• AGN wind scaling relations and the co-evolution of black holes and galaxies (2017, background): “…Zakamska et al. 2016); 2) interferometric observations in the (sub)millmetre domain (e.g. Feruglio et al. 2010, 2013a,b, 2015; Alatalo et al. 2011; Aalto et al. 2012; Cicone et al. 2012, 2014, 2015; Maiolino et al. 2012, Krips et al. 2011; Morganti et al. 2013a,b; Combes et al. 2013;…”
• The multi-phase winds of Markarian 231: from the hot, nuclear, ultra-fast wind to the galaxy-scale, molecular outflow (2015, background): “In fact, this would provide a ratio HCN/H13CN(1−0) ∼ 8, based on the strength of HCN(1-0) measured by Aalto et al. (2012), i.e., a factor of five smaller than the isotopic 12C/13C ratio of 40 found by us.”
• THE MULTIPHASE STRUCTURE AND POWER SOURCES OF GALACTIC WINDS IN MAJOR MERGERS (2013, background): “The winds in ULIRGs also have a molecular component (Fischer et al. 2010a; Feruglio et al. 2010; Sturm et al. 2011; Aalto et al. 2012; Cicone et al. 2012, Veilleux et al. 2013, in prep.).”
• FAST MOLECULAR OUTFLOWS IN LUMINOUS GALAXY MERGERS: EVIDENCE FOR QUASAR FEEDBACK FROM HERSCHEL (2013, background): “In a few of these objects, particularly those with dominant AGN such as Mrk 231, the nearest quasar known, the terminal outflow velocities exceed 1000 km s−1 and the outflow rates (up to ∼1000 M⊙ yr −1) are several times larger than the infrared-based SFRs. (2) Independent, spatially resolved CO-emi”
• The Coevolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe (2014, methodology): “The molecular outflow in the proto-typical AGN-dominated ULIRG Mrk 231 has been mapped in CO (Feruglio et al. 2010, Cicone et al. 2012) and HCO+, HCN, and HNC (Aalto et al. 2012) using the Plateau de Bure mm-wave interferometer.”
• Evidence of strong quasar feedback in the early Universe (2012, background): “…outflows observed locally are characterized by a wide range of densities, including both dense clumps and diffuse, low density gas (Cicone et al. 2012; Aalto et al. 2012; Fischer et al. 2010), therefore our assumption on the gas density gives a conservative lower limit on the outflowing gas mass.”
• Molecular line emission in NGC 1068 imaged with ALMA: I. An AGN-driven outflow in the dense molecular gas (2014, background): “…of nearby active galaxies including ultra luminous infrared galaxies (ULIRGs), radio galaxies, and Seyferts (Feruglio et al. 2010; Sturm et al. 2011; Alatalo et al. 2011; Chung et al. 2011; Aalto et al. 2012; Dasyra & Combes 2012; Combes et al. 2013; Morganti et al. 2013; Cicone et al. 2012, 2014).”
• Massive molecular outflows and evidence for AGN feedback from CO observations (2013, background): “…in local AGN hosts and ultra-luminous infrared galaxies (ULIRGs; Feruglio et al. 2010; Fischer et al. 2010; Sturm et al. 2011; Alatalo et al. 2011; Aalto et al. 2012a; Cicone et al. 2012; Dasyra & Combes 2012; Nesvadba et al. 2010, 2011; Veilleux et al. 2013; Spoon et al. 2013; González-Alfonso…”
• Very extended cold gas, star formation and outflows in the halo of a bright QSO at z>6 (2014, background): “…particular, of massive kpcscale outflows of cold and dense molecular gas in nearby galaxies (Feruglio et al. 2010, 2013a,b; Alatalo et al. 2011; Sturm et al. 2011; Aalto et al. 2012; Veilleux et al. 2013; Spoon et al. 2013; Combes et al. 2013; Cicone et al. 2012, 2014; GarcíaBurillo et al. 2014).”
• The molecular gas in Luminous Infrared Galaxies I: CO lines, extreme physical conditions, and their drivers (2011, background): “Finally the recent discovery of a massive molecular gas outflow, likely driven by the AGN in Mrk 231, by Aalto et al. (2012) inserts an exciting new element in this debat by demonstrating that much higher density gas (>104 cm−3) can also be affected by AGN feedback.”