der Paul van der Werf Leiden Observatory Radiative and mechanical feedback in the molecular gas in (U)LIRGs London September 16, 2011

Credits Kate Isaak (ESTEC) Padelis Papadopoulos (MPI für Radioastronomie) Marco Spaans (Kapteyn Astronomical Institute) Eduardo González-Alfonso (Henares) Rowin Meijerink (Leiden Observatory) Edo Loenen (Leiden Observatory) – talk after tea Alicia Berciano Alba (Leiden Observatory/ASTRON) – next talk Axel Weiß (MPI für Radioastronomie) + the HerCULES team 2 Feedback in (U)LIRGs

Outline   Introducing HerCULES   H 2 O emission in (U)LIRGs   Radiation pressure dominated disks in (U)LIRGs 3 Feedback in (U)LIRGs

Introducing HerCULES 4 Herschel Comprehensive (U)LIRG EmissionSurvey Open Time Key Program on the Herschel satellite Feedback in (U)LIRGs

HerCULES in a nutshell   HerCULES measures uniformly and statistically the neutral gas cooling lines in a flux-limited sample of 29 (U)LIRGs.   Sample:   all IRAS RBGS ULIRGs with S 60 > Jy (6 sources)   all IRAS RBGS LIRGs with S 60 > 16.8 Jy (23 sources)   Observations:   SPIRE/FTS full high-resolution scans: 200 to 670  m at R ≈ 600, covering CO 4 — 3 to 13 — 12 and [CI] + any other bright lines   PACS line scans of [CII] and both [OI] lines   All targets observed to same (expected) S/N   Extended sources observed at several positions 5 Feedback in (U)LIRGs

Who is HerCULES? Paul van der Werf (Leiden; PI) Susanne Aalto (Onsala) Lee Armus (Spitzer SC) Vassilis Charmandaris (Crete) Kalliopi Dasyra (CEA) Aaron Evans (Charlottesville) Jackie Fischer (NRL) Yu Gao (Purple Mountain) Eduardo González-Alfonso (Henares) Thomas Greve (Copenhagen) Rolf G ü sten (MPIfR) Andy Harris (U Maryland) Chris Henkel (MPIfR) Kate Isaak (ESA) Frank Israel (Leiden) Carsten Kramer (IRAM) Edo Loenen (Leiden) Steve Lord (NASA Herschel SC) Jesus Martín-Pintado (Madrid) Joe Mazzarella (IPAC) Rowin Meijerink (Leiden) David Naylor (Lethbridge) Padelis Papadopoulos (Bonn) Dave Sanders (U Hawaii) Giorgio Savini (Cardiff/UCL) Howard Smith (CfA) Marco Spaans (Groningen) Luigi Spinoglio (Rome) Gordon Stacey (Cornell) Sylvain Veilleux (U Maryland) Cat Vlahakis (Leiden/Santiago) Fabian Walter (MPIA) Axel Wei ß (MPIfR) Martina Wiedner (Paris) Manolis Xilouris (Athens) 6 Feedback in (U)LIRGs

HerCULES sample Target log(L IR /L  ) Mrk IRAS F17207— IRAS 13120— Arp Mrk IRAS F05189— Arp NGC IRAS F18293— Arp IC NGC NGC NGC Target log(L IR /L  ) IC 4687/ NGC NGC MCG+12—02— Mrk IRAS 13242— NGC Zw NGC NGC IRAS F11506— NGC NGC NGC NGC Feedback in (U)LIRGs

Outline   Introducing HerCULES   H 2 O emission in (U)LIRGs   Radiation pressure dominated disks in (U)LIRGs 8 Feedback in (U)LIRGs

Water in molecular clouds  H 2 O ice abundant in molecular clouds  Can be released into the gas phase by UV photons, X-rays, cosmic rays, shocks,...  Can be formed directly in the gas phase in warm molecular gas  Abundant, many strong transitions  expected to be major coolant of warm, dense molecular gas 9 Feedback in (U)LIRGs Herschel image of (part of) the Rosetta Molecular Cloud

Feedback in (U)LIRGs 10 Low-z H 2 O: M82 vs. Mrk231  At D = 3.9 Mpc, one of the closest starburst galaxies  With L IR = 3  L , a very moderate starburst  At z=0.042, one of the closest QSOs (D L =192 Mpc)  With L IR = 4  L , the most luminous ULIRG in the IRAS Revised bright Galaxy Sample M82Mrk231

H 2 O lines in M82  Faint lines, complex profiles  Only lines of low excitation 11 Feedback in (U)LIRGs (Weiß et al., 2010)(Panuzzo et al., 2010)

Mrk231: strong H 2 O lines, high excitation 12 Feedback in (U)LIRGs (Van der Werf et al., González- Alfonso et al., 2010)

Mrk231: details 13Feedback in (U)LIRGs New detections:  H 2 O ground state  H 2 18 O (2 lines)  H 3 O + (3 lines)  NH 3  NH 2 ?  several unassigned lines

H 2 O lines in Mrk231  Low lines: pumping by cool component + some collisional excitation  High lines: pumping by warm component  Radiative pumping dominates and reveals an infrared-opaque (  100  m ~ 1) disk. (González-Alfonso et al., 2010) 14 Feedback in (U)LIRGs

Lessons from H 2 O (1 + 2) 15Feedback in (U)LIRGs 1) In spite of high luminosities, H 2 O lines are unimportant for cooling the warm molecular gas. 2) Radiatively H 2 O lines reveal extended infrared-opaque circumnuclear gas disks.

Lessons from H 2 O (3) Radiation pressure from the strong IR radiation field: 16Feedback in (U)LIRGs Since both  100 and T d are high, radiation pressure dominates the gas dynamics in the circumnuclear disk. 3) Conditions in the circumnuclear molecular disk are Eddington-limited.

Eddington-limited consequences   Eddington-limited conditions predict the L FIR -L HCN relation within factor 2 for standard dust/gas ratio (Andrews & Thompson 2011)   If accreting towards nuclear SMBH, can account for M * /M  relation (Thompson et al., 2005)   Radiation pressure can expel nuclear fuel and produce Faber- Jackson relation (Murray et al., 2005) 17 Feedback in (U)LIRGs (Andrews & Thompson, 2011)

Mechanical feedback   Radiation pressure can drive the observed molecular outflows (e.g., Murray et al., 2005)   See Susanne Aalto’s talk: flow prominent in HCN  dense gas   Highest outflow velocities observed in H 2 O   Key process in linking ULIRGs and QSOs? 18 Feedback in (U)LIRGs (Feruglio et al., 2010) (Fischer et al., 2010)

H 2 O in HerCULES Target log(L IR /L  ) Mrk IRAS F17207— IRAS 13120— Arp Mrk IRAS F05189— Arp NGC IRAS F18293— Arp IC NGC NGC NGC Target log(L IR /L  ) IC 4687/ NGC NGC MCG+12—02— Mrk IRAS 13242— NGC Zw NGC IRAS F11506— NGC NGC NGC NGC Feedback in (U)LIRGs red = wet

Sample spectrum: Zw049  Feedback in (U)LIRGs

Zw049  057 details 21Feedback in (U)LIRGs

H 2 O is not XDR-driven 22Feedback in (U)LIRGs  Only 3 bona fide AGNs in H 2 O sample (Mrk231, IRAS F05189  2524, and Arp299A)  Some pure starbursts in H 2 O sample (e.g., IRAS  0014)  AGNs without strong H 2 O emission (e.g., NGC1365, NGC7469)  NGC7469 shows no strong H 2 O lines but strong OH + emission  XDR?  All of this must be compared to CO ladder PDR/XDR analysis

Luminosity dependence   Radiatively excited H 2 O emission ubiquitous in ULIRGs, but also seen in some LIRGs (young starbursts?)   Detection of weak H 2 O lines in many LIRGs and in M82 shows plenty of gas-phase H 2 O  key feature is the prominence of infrared-opaque clouds 23 Feedback in (U)LIRGs

Outline   Introducing HerCULES   H 2 O emission in (U)LIRGs   Radiation pressure dominated disks in (U)LIRGs 24 Feedback in (U)LIRGs

The X-factor   Converting CO flux (luminosity) into H 2 column density (mass): (MW:  =4; ULIRGs:  =0.8) Warning: discussions of the X- factor have been the death-blow for many conferences. 25 Feedback in (U)LIRGs (Papadopoulos, Van der Werf, Isaak & Xilouris, in prep. ) (U)LIRG sample

The X-factor and optical depth Highly turbulent motions  low optical depths (  high 12 CO/ 13 CO line ratios)  low X-factor (e.g., ULIRGs: X=0.8,Downes & Solomon 1997) 26 Feedback in (U)LIRGs NB: T line is T b of the line, not kinetic temperature

Calculating X-factors   Sample of 70 (U)LIRGs, 12 CO 1  0, 2  1, 3  2, (4  3, 6  5) and 13 CO 1  0, (2  1) lines   2 component model: high excitation and low excitation component   X-factor explicitly calculated using non-LTE excitation model and finite optical depths 27 Feedback in (U)LIRGs

Distribution of X-factors Assumptions:   Orion-like high excitation component (not needed with denser coverage of CO ladder  Herschel)   Radiation pressure supported disk  L FIR /M(star forming gas) = constant (observed: L FIR /L HCN = constant; e.g., Gao & Solomon, Wu et al.) Results:   X-factors cluster between 0.5 and 1 (cf., Downes/Solomon value of 0.8 for ULIRGs) with tail up to and exceeding Milky Way values   Most (but not all!) ULIRGs have low X-factors 28 Feedback in (U)LIRGs (Papadopoulos, Van der Werf, Isaak & Xilouris, in prep. ) (U)LIRG sample

Getting at X   Derive X from 12 CO 1  0  6  CO 1  0 (or 2  1); ideally, use HCN lines as well   Can be used at high z too, but 13 CO is challenging   Why did Downes & Solomon get it right without 13 CO?   High quality data showing turbulent velocity field   Correctly produced low optical depth   Getting the optical depth right is key 29 Feedback in (U)LIRGs

Summary and outlook   Radiatively excited H 2 O lines select infrared-opaque nuclear regions such as found in local ULIRGs.   IR radiation pressure can be an important dynamical factor and may lead to Eddington- limited star formation.   X-factors in these regions can be derived from CO lines   Rich field for ALMA at low and high z 30 Feedback in (U)LIRGs