Theme IV: Nearby Galaxies Theme IV: Nearby Galaxies and the Galactic Centerand the Galactic Center

Lead - G.J. Stacey

Cornell University

Deputy - W. Vacca

USRA

Team MembersTeam Members

Gordon Stacey (Cornell) Formal Lead Science: Far-IR and submm spectroscopy of galaxies,

Galactic starformation regions, Galactic Center Experience: KAO/ISO/JCMT – CSO Investments: SOFIA (FORCAST/SAFIRE) Unique Strength: Submm lines, Instrumentation

Bill Vacca (USRA) SOFIA Lead Science: UV/Optical/Near IR spectroscopy & photometry

galaxies, star clusters, massive stars Experience: HST/Keck/IRTF/Gemini/Spitzer Investments: SOFIA Unique Strength: Optical studies, Stellar Populations

Team MembersTeam Members

Sue Madden (CEA/Saclay) Science: Mid/far-IR and spectroscopy and photometry of

galaxies , Galactic star formation regions, Galactic Center Experience: KAO/ISO (LWS/ISOCAM) Investments: Herschel (SPIRE/PACS) Unique Strength: Dwarf Galaxies, Dust continuum

Mark Morris (UCLA) Science: Multi-wavelength studies of the Galactic Center Experience: KAO/VLA/HST/Keck/Chandra/Spitzer Investments: SOFIA Unique Strength: Galactic Center

Team MembersTeam Members

Linda Tacconi (MPE) Science: Multi-wavelength spectroscopy of AGN/high z

galaxies Experience: FCRAO/JCMT/VLT/ISO(SWS) Spitzer IRAM

Interferometer Investments: Herschel (PACS) Unique Strength: Molecular gas in high z galaxies

Mark Wolfire (Maryland) Science: Theory – PDR/XDR and HII region modeling –

Galactic star formation regions, Galactic Center, galaxies Experience: KAO/ISO/Spitzer Investments: SOFIA Unique Strength: Theory, modeling

Activities Activities Team assembled in April/May

Held several telecons: Wed at 9 AM (PDT)

June 11, June 18, July 2, July 9, July 15

Divided ‘Theme’ into 4 major topics (based on ideas from initial telecons and Gordon’s talk at the last review)

Assigned topics to individuals to present (via Powerpoint slides) to the group and lead the discussion Presentations on 2 topics so far

Responsible person(s) to write up text on topic, incorporating comments from group We have initial drafts of text on 2 topics

Science Topics within Theme IVScience Topics within Theme IV

Tracing the ‘Extinction-Free’ Evolution and Star Formation History of Galaxies in the local Universe, at redshifts 0 - 1 (Gordon Stacey) ‘Low-redshift Cosmology’

Studying the Circumnuclear Disk and Magnetic Fields of the Galactic Center (Mark Morris) The GC as a template for AGN

Determining the conditions in the Tori of nearby Active Galactic Nuclei (Mark Wolfire)

Nearby Galaxies (Sue Madden & Bill Vacca)Feedback (W. Matthews & Pasquale Temi)

Galaxy Spectral Energy Distribution Galaxy Spectral Energy Distribution (SED)(SED)

SOFIA

SOFIA StrengthsSOFIA Strengths Resolving power:

Uniquely high between 5 to 28 and 100 to 700 m (EXES, SAFIRE)

Wavelength coverage: 9 octaves of wavelength coverage (1 to 700 m) Covers the peak of dust SED in starburst galaxies Post-Spitzer, near unique coverage from ~5 m (until

JWST, then 28 m) through 60 m (Herschel) Host of diagnostic lines from 5 to 60 m, including (post

Spitzer) SOFIA-unique lines with FORCAST and FIFI-LS: [SIII] 33 m, [SiII] 35 m, [NeIII] 36 m, [OIII] 52 m, [NIII] 57 m

Evolution of Galaxies at 0 < z < 1Evolution of Galaxies at 0 < z < 1 FIR Fine-Structure lines provide ‘extinction-free’ estimates of

strength and hardness of ionizing radiation– Distinguish between stars and AGN in dusty objects (e.g. ULIRGs)– Determine SFR and trace evolution of SFR with z

L([CII])/L(FIR) provides an estimate of size of starburst– Local (regional) starbursts at z~0 to global (galaxy-wide) at z~1

Blain et al 2002

SOFIA’s Regime

Ground based windows for [CII] 158 m

‘Extinction-corrected’ estimates of SFR/vol.

from optical/NIR

Evolution of Galaxies at 0 < z < 1Evolution of Galaxies at 0 < z < 1

Near unique niches for studying the epoch from the peak of the star formation per unit volume through to today’s universe z ~ 0 to 1 for [CII] 158 m line – major gas coolant, probes

PDRs, G, intensity, size of starburst z ~ 0 to 1 for [NII] 205 m line – probes low density HII

regions, proxy for Lyman continuum photons, separates [CII] fraction from ionized gas.

z > 2 [OI] 63 m studies – major PDR gas coolant, probes dense PDRs, G, size of starburst

SAFIRE is quite competitive with Herschel (especially if SAFIRE is a grating spectrometer – otherwise a next generation spectrometer can fully exploit this sensitivity niche)

Evolution of Galaxies at 0 < z < 1Evolution of Galaxies at 0 < z < 1 SOFIA/SAFIRE is uniquely positioned for observations of FIR fine-structure lines (e.g., [OI],

[O III], [CII], [NII]) in the critical range 0 < z < 1 Several hundred sources should be accessible from various surveys SOFIA will determine the true SFR history of the local Universe

1.E+10

1.E+11

1.E+12

1.E+13

0.00 0.50 1.00 1.50

Redshift

L(far-IR)

SOFIASAFIRE

Herschel HI-FI

[CII] 158 m 5 detection in 2 hours

Galactic Center: A Local Template Galactic Center: A Local Template for (Active) Galactic Nucleifor (Active) Galactic Nuclei

Most galaxies contain Super Massive Black Holes at their centers. The GC is the closest example and serves as the local template for more distant (active) galactic nuclei.

How is the SMBH fed? (What are the detailed physical processes involved in accretion onto the BH?) What are the properties of and

conditions in the Circum-nuclear Disk (CND) and how do they affect SF and accretion?

How does CND evolve? What heats the gas in the GC? What roles do shocks and

turbulence play? What role does the B field play?

Galactic Center: Circumnuclear DiskGalactic Center: Circumnuclear Disk Circumnuclear Disk (CND) is a

reservoir for material accreting onto the central BH Both star formation and accretion

are occurring inside inner edge Properties can be studied with almost

all of SOFIA’s instruments Sensitivity is not an issue EXES will provide unique access to

pure rotational lines of H2 at 12, 17, and 28 m and distinguish emission from different clouds to determine temps and masses

Extensive mapping with SOFIA instruments will allow large scale perspective of events and conditions around a SMBH

Large scale mapping can’t be done with Herschel

KIWC/KAO Latvakoski et al. 1999

FORCAST 38 m beam

Galactic Center: Magnetic FieldsGalactic Center: Magnetic Fields GC has strong B fields which

affect accretion and star formation

Magnetic field measurements using HAWC polarimeter The 7" beam (@ 60 m) would

provide the best measure yet of the GC magnetic field strength

The magnetic field direction in the warmest clouds (including the CND) would be determined from the orientation of the polarization vectors.

Far IR polarimetry with a large FOV and good spatial resolution would be a truly unique capability!

60, 100 m polarimetry with KAO350 m polarimetry with CSO

2003

Tori of Active Galactic NucleiTori of Active Galactic Nuclei

Torus very warm (1000 K), and very dense (~ 107 cm-3) strong neutral line emission (CO, [OI], H2O)

Typical source @ 100 Mpc: FJ=17-16 ~ 6 10-18 W-m-2

High-J CO lines are clear signatures and primary coolants of the confining torus – and are very sensitive to the physical conditions of the torus

SOFIA Advantage: CO SED from J ~ 7-6 to J > 58 (46 m)!

Artist’s conception of the doughnut shaped torus that confines the emission from an active nucleus (Credit ESA).

Star Formation in Nearby Galaxies Star Formation in Nearby Galaxies Spitzer/IRAC @ 8 m ≈ SOFIA/FORCAST @ 24 m

How do stars form in galaxies? The formation of ‘Super Star Clusters’ (SSCs) is major mode of Star Formation in galaxies All stars in a galaxy may form in SSCs! ‘Buried’ SSCs are young massive clusters still enshrouded in natal material, invisible in optical/NIR

FORCAST (grisms) and EXES give 3x better spatial resolution than Spitzer Measure Te, Ne, Z, AV, excitation Constrain stellar pops/IMF, ages, masses, dust properties Study winds and feedback from winds on environment Sensitivity generally not an issue

ScheduleSchedule

Next telecon (on Nearby Galaxies) Additional telecons Collect written drafts on topics Group will comment on written text Full (initial) draft of theme document Revise draft Prepare PPT slides

July 21

Wed. @ 9am PDT

End July / Beg Aug

August 13

October 1