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[CII] in the nuclear region of M33: HerM33es Bhaswati Mookerjea Tata Institute of Fundamental Research, Mumbai, India C+ Workshop, Leiden, 7 February 2013 HerM33es: [CII] Outer HII region BCLMP691 BCLMP302 Nucleus Southern Arm 07/02/2013, Leiden Hα (color) together with PACS footprints (green) and HIFI onthe-fly cuts. [CII] in M33-Nucleus [CII] Spectra in M33 BCLMP691 Braine et al. (2012) BCLMP302 Mookerjea et al. (2011) Compared with VLA HI & IRAM CO(2-1) at 12” resolution Southern Arm Kramer et al. (in prep) 07/02/2013, Leiden [CII] in M33 nucleus 600 pc ISM in the M33 Nucleus ● Unspectacular nucleus ● GMCs with HII regions ● 12'' @ 840pc → 50 pc CO, HI and dust continuum emitting clouds match well ● MIPS 24 μm (Color) HI (Black) CO(2-1) (White) 600 pc 07/02/2013, Leiden CO(2-1) IRAM/HERA [CII] in M33 & HI VLA (Gratier etnucleus al. 2010) HIFI [CII] cuts in the nucleus of M33 07/02/2013, Leiden [CII] in M33-Nucleus HIFI [CII] cuts in the nucleus of M33 Nikola et al. (in prep) 07/02/2013, Leiden [CII] in M33-Nucleus [CII] in M33 nucleus Fully sampled loadchopped perpendicular OTF cuts ● Extracted spectra at 30 positions on a 10” grid ● 07/02/2013, Leiden [CII] in M33-Nucleus Average spectrum Average spectrum shows at least 3 velocity components ● Velocity components correspond to the different HII regions (continuum peaks) sampled by the cuts ● Reasonable (but not complete) agreement with CO(2-1) ● HI emission seems to have the components blended together ● Average is over too large (and dynamic) an area ● 07/02/2013, Leiden [CII] in M33-Nucleus Position-Velocity Diagram along Minor Axis ● [CII] & CO match HI shows shift in velocity & enhanced emission to the NW ● 07/02/2013, Leiden [CII] in M33-Nucleus PV Diagram along Major Axis Clear & large velocity gradient (~ 50 km/s over 120”) ● Change in velocities at the HII regions ● Good correspondence with CO(2-1) & HI with a slight shift ● 07/02/2013, Leiden [CII] in M33-Nucleus [C II] Spectra [C II] clearly detected in 21 out of 30 positions on a 10” grid on the cuts ● Lineshapes mostly fitted by one or two Gaussians ● At all positions but one HI & CO (21) detected for one of the two velocity components seen in [C II] ● HI CO(2-1) CII 07/02/2013, Leiden [CII] in M33-Nucleus [C II]/CO/HI Comparison 07/02/2013, Leiden [CII] in M33-Nucleus Comparison of Velocities Component 1: --- [C II] emitting gas also emits CO at all positions and HI at all but one position --- Match with Hα velocities to the east ● Component 2: --- Seen at 12 ([CII]), 10 (CO) and 8 (HI) positions --- At 10 positions [C II] but no CO at the same/similar velocities … only 3 show HI emission ● 07/02/2013, Leiden [CII] in M33-Nucleus Velocities of Component 1 Discrepancy between [C II] and CO and HI lines mostly < 3 km/s 07/02/2013, Leiden [CII] in M33-Nucleus CNM contribution to [CII] emission (Comp. 1) 07/02/2013, Leiden [CII] in M33-Nucleus CNM contribution <20% for most positions CII/CO Ratio (Comp. 1) Ratio < 20000 at most positions BCLMP302: 6000-30000 BCLMP691: 07/02/2013, 8000 Leiden [CII] in M33-Nucleus Typical low-metallicity galaxies: LMC (23000) Gas Heating Efficiency in the M33 nucleus TIR (1 μm to 1mm) luminosity linearly related to the 160 μm PACS luminosity --- Boquien et al. (2011) ● Derived TIR for the nucleus region on a 12” grid ● Both components of CII where present are used ● [CII]/TIR ratio of intensities lies between 0.1 and 1.8% ● 07/02/2013, Leiden [CII] in M33-Nucleus Gas Heating Efficiency in the M33 nucleus TIR (1 μm to 1mm) luminosity linearly related to the 160 μm PACS luminosity --- Boquien et al. (2011) ● Derived TIR for the nucleus region on a 12” grid ● Both components of CII where present are used ● [CII]/TIR ratio of intensities lies between 0.1 and 1.8% ● 07/02/2013, Leiden [CII] in M33-Nucleus Summary Clear large velocity gradients detected in [CII] close to the M33 nucleus ● [CII], CO(2-1) and HI profiles vary significantly --- need to compare gas with similar velocities ● ● Major component of [CII] emitting gas is also detected in CO and HI ● Evidence for [CII] emission without corresponding CO or HI ● Matching of Hα velocities with [CII] ---> the ionized gas contribution ● Estimated contribution of CNM to [CII] emission ~ 15-20% ● High [CII]/CO ratios typical of low-metallicity environments ● 07/02/2013, Leiden [CII]/TIR between [CII] incomparable M33-Nucleus to other regions of M33 0.1 to 1.8%,