red stellar populations IR spectra abundance patterns & kinematics extreme environments - galactic bulge - galactic bulge - young extragalactic clusters - young extragalactic clusters - SB galaxies - SB galaxies
resolved resolved into single stars : in galaxy fields up to a few Mpc in stellar clusters within the LG integrated integrated: stellar clusters up to a few Mpc galaxies pop synthesis multiple ages, metallicities NGC1569 – SSCs H HST – NICMOS D = 2.2 Mpc d SSC 100 mas d SSC 100 mas Aloisi et al. 2001, AJ 121, 1425 Aloisi et al. 2001, AJ 121, 1425 Origlia et al. 2001, AJ 122, 815 Origlia et al. 2001, AJ 122, 815 M31 – G1 HST – ACS D = 0.77 Mpc d G1 a few arcsec d G1 a few arcsec
each sequence in the most suitable range hot in the UV-optical, cool in the IR hot in the UV-optical, cool in the IR larger baseline better definition of stellar & population parameters better definition of stellar & population parameters temperature, gravity, metallicity, mass, IMF, reddening etc. nebular vs stellar contributions, mass loss, SF rates etc. each environment in the most suitable range metal poor, low reddening (e.g. halos) in the UV-optical metal poor, low reddening (e.g. halos) in the UV-optical metal rich, high reddening (e.g bulges) in the IR metal rich, high reddening (e.g bulges) in the IR
Post-Main Sequence stars Red Supergiant (RSG): 8-40 M o, age Myr Asymptotic Giant Branch (AGB): 100 Myr Red Giant Branch (RGB ): few Gyr in the near IR dominate the stellar luminosity of stellar clusters & normal galaxies over the nebular & AGN emission in active galaxies T eff < 5000 K
chemical abundances & abundance patterns of Fe,CNO, -elements SF history, timescales, rates, etc., primordial vs self-enrichment etc. SF history, timescales, rates, etc., primordial vs self-enrichment etc. radial velocities & velocity dispersions distances, masses, dynamical interactions etc. distances, masses, dynamical interactions etc. near IR range crucial to study: galaxy bulges galaxy bulges extragalactic star clusters extragalactic star clusters young SSCs & star forming galaxies young SSCs & star forming galaxies host galaxies of both type I & II AGNs host galaxies of both type I & II AGNs optimal spectral resolutions: stars & stellar clusters: 1-10 Km/s galaxies: Km/s
neutral atomic lines Fe, Si, Ca, Mg, Ti, Al, Na neutral atomic lines Fe, Si, Ca, Mg, Ti, Al, Na
OH, CO, CN molecular bands very sensitive to C, O & N abundances OH, CO, CN molecular bands very sensitive to C, O & N abundances
the SF history of a stellar system is imprinted in their chemical abundance patterns elements: O, Si, Ca, Mg,Ti type II SNe with massive progenitors type II SNe with massive progenitors released in the ISM from the very beginning of the SF onset Fe - group elements type I SNe with intermediate mass progenitors type I SNe with intermediate mass progenitors C, N, s,r-process elements AGB with low-intermediate mass progenitors AGB with low-intermediate mass progenitors released in the ISM after 1 Gyr from the SF onset released in the ISM after 1 Gyr from the SF onset
elements: O, Si, Ca, Mg, Ti [ /Fe] [Fe/H] IMF SFR Galactic Halo stars formed from a gas mainly enriched by SNII on a relatively short timescale Galactic Disk stars formed from a gas also enriched by SNIa on a much longer timescale Galactic Bulge ?
Optical spectra see e.g. Fullbright, McWilliam & Rich ‘06; Zoccali et al. ‘06 K giants: (V-K) K red clump at V 0 15 outer Bulge with A v < 2 M giants: severly affected by molecular blanketing & blending IR spectra K giants: too warm, faint lines M giants: (V-K) 0 >3, T eff <4000 K RGB Tip inner Bulge, A IR negligible luminosity temperature RGB Tip HB
SURVEY of cluster & field M giants in collaboration with R.M. Rich & E. Valenti H band ( micron) echelle spectra with NIRSPEC at Keck II
[ /Fe] enhancement
elements: O, Si, Ca, Mg, Ti [ /Fe] [Fe/H] IMF SFR Galactic Halo stars formed from a gas mainly enriched by SNII on a relatively short timescale Galactic Disk stars formed from a gas also enriched by SNIa on a much longer timescale Galactic Bulge, E gal halo – like but at higher SFR
NGC 6946 NGC 6946 F555W F555W 6945 SSC D = 5.9 Mpc = 10.4 km/s M = 1.7 x 10 6 M o age = Myr L/M consistent with a Salpeter IMF Larsen et al. 2001, ApJ, 556, 801
Larsen, Origlia, Brodie & Gallagher, 2006, MNRAS, 368, 10 = 9.1 km/s [Fe/H] = /- 0.1 [Ca,Mg,Al/Fe] = / [O,Ti/Fe] = / [Si/Fe] = / [C/Fe] = / C/ 13 C = 8 +/- 2 NGC 6946 – SSC NGC 6946 – SSC R=25,000 R=25,000
… calibrating suitable stellar abundance tracers for integrated spectroscopy of distant galaxies for integrated spectroscopy of distant galaxies velocity dispersion / rotation line broadening velocity dispersion / rotation line broadening
in the visual range: SB galaxies severely contaminated by nebular emission and AGN in the near - IR range: SB galaxies poorly contaminated by nebular emission and AGN RSGs dominate the luminosity
diagnostics : stellar vs gaseous abundances stars (red supergiants) in the IR: enrichment before the last burst of SF hot gas in the X-ray with Chandra & XMM: real-time enrichment by the last burst of SF cool gas in the visual: enrichment by the previous or the last burst of SF? it depends on the cooling & mixing timescales…
near–IR: TNG/NICS X ray: XMM RGS/MOS M 82 NGC 253
near–IR spectra X-ray spectra T eff = 3800 – 4000 K log g = 0.5 = 3 km/s point sources power law =0.8 N H = 8x10 21 cm -2 diffuse hot gas optically thin thermal plasma kT=0.7 kev N H = 4x10 21 cm -2 T eff = +/- 200 K log g = +/- 0.5 = +/- 1 km/s [X/H] = +/- 0.2 dex 2 level best-fit models
chemical enrichment by recursive bursts oxygen puzzling … [Fe/H] = /- 0.2 stars: [Si,Mg/Fe] = +0.4 [O/Fe] = +0.4 hot gas: [Si,Mg/Fe] = +0.5 [O/Fe] = 0.2 M 82 [Fe/H] = /- 0.2 stars: [Si,Mg/Fe] = +0.3 [O/Fe] = +0.3 hot gas: [Si,Mg/Fe] = +0.7 [O/Fe] = 0.1 NGC 253 Origlia et al. 2004, ApJ, 606, 862
oxygen underabundance working hypothesis (Marcolini,, Strickland, D’Ercole, Heckman & Hoopes, 2005, MNRAS, 362, 626) SNII winds interact with cool gas clouds & and heat them heavier metals (Si, Mg etc.) form in the SNII wind X O forms in the outer region of the wind (OVII & OVIII soft X ) UV and/or in the heated clouds (OV & OVI UV )
IR spectroscopy crucial to measure star kinematics in type I AGNs
near IR dust optically thin emission volume near IR dust optically thin emission volume L dust (SB ) L dust (AGN ) / N L dust (SB ) L dust (AGN ) / N stellar clusters less efficient than AGN in heating dust stellar clusters less efficient than AGN in heating dust M BH – relation Merritt & Ferrarese 2001, ApJ, 547, 140 Gebhardt et al. ‘01 Ferrarese & Merritt ‘00 M BH M BH 4.8 0.5
M/L stellar :burst on/off hosts of AGNs hosts of AGNs no nuclear SB in Seys 1 nuclear SB in 30 – 40 % obscured / Seys 2 obscured / Seys 2 Oliva et al., 1999, A&A 350, 4 Origlia & Oliva, 2000, New Astr. Rev. 44, 25
( Cid Fernandes et al. 2001, ApJ 558, 81) 35 type II Seyferts 35 type II Seyferts morphological type: S0, Sa, Sb stellar content: 50% nuclear SB (< 1 kpc scale ), 50% old SP correlation between SB (H & AGN ([OIII]) luminosity ( Kauffman et al. 2003, MNRAS 346, 1055) ( Kauffman et al. 2003, MNRAS 346, 1055) 22,600 narrow-line AGNs 22,600 narrow-line AGNs type 2 Seys & QSOs with same [OIII] and z have similar hosts
in massive SB galaxies RSGs dominate over an underlying older SP 1.0 < [Fe/H] < 0.0, 8<age<50 Myr T eff 3600 – 4000 K log g 0.0 – 1.0 3 5 km/s T eff = 3800 200 K log g = 0.5 0.5 4 1 km/s [A/H] = 0.2 dex in the near IR: young SPs: red supergiants intermediate/old SPs: red giants intermediate/old SPs: red giants stellar parameters: from young MC clusters
code : Origlia et al. (1993 code : Origlia et al. (1993 2004 model atmospheres : ATLAS9, Johnson et al. ’80, NextGen, [Plez] stellar parameters : near IR photometry + molecules LTE full spectral synthesis equivalent width measurement of selected lines
< 0.1 dex spectral fitting/equivalent width measurements < 0.1 dex log gf dex log gf 0.2 0.1 dex random errors: dex stellar parameters dex dex solar abundances 0.1 0.1 dex systematic errors: nLTE corrections negligible at T>3000 K nLTE corrections negligible at T>3000 K negligible, opacity dominated by H - model atmospheres negligible, opacity dominated by H - other sources of error:
[OI] lines ( 6300,6364 ) [OI] lines ( 6300,6364 Å ) OI triplet ( 7772,7774,7775 ) OI triplet ( 7772,7774,7775 Å ) OH molecular transitions OH molecular transitions IR lines ( m ) IR lines ( m ) low temperatures, high metallicity domain
bulge
vertical abundance gradients ? vertical abundance gradients ? observing old SPs in the galactic center observing old SPs in the galactic center self-enrichment as traced by O-Na & Mg-Al anti-correlation ? perhaps yes … perhaps yes … Mg-Al anti-correlation
12 C/ 13 C 10 extra - mixing
halo bulge
halo bulge 40 clusters 25% of the entire GGC system) 0.1 < E(B-V) < 3.5, 50% metal-rich To trace the Bulge physical & chemical evolution To test the stellar models in the high metallicity domain To construct high metallicty templates for ellipticals
nebular spectra
emission lines: [OII] [OIII] [NII] [SII] best n e,T e diagnostics (e.g. McCall, 1984, MNRAS 208, 253) : n e I ([SII] I ([SII] T e [++] I ([OIII] I ([OIII] T e [+] I ([NII] I ([NII] emission lines: [OII] [OIII] [NII] [SII] best n e,T e diagnostics (e.g. McCall, 1984, MNRAS 208, 253) : n e I ([SII] I ([SII] T e [++] I ([OIII] I ([OIII] T e [+] I ([NII] I ([NII] alternative T e diagnostics at high Z : (e.g. Pagel et al., 1979, MNRAS, 189, 95 Storchi-Bergmann et al. 1994, ApJ429, 572) empirical calibrations alternative T e diagnostics at high Z : (e.g. Pagel et al., 1979, MNRAS, 189, 95 Storchi-Bergmann et al. 1994, ApJ429, 572) empirical calibrations abundances at high Z : (McGaugh, 1991, ApJ 380, 140) empirical calibrations abundances at high Z : (McGaugh, 1991, ApJ 380, 140) empirical calibrations
NGC 1569 Balmer Balmer jump jump HeII bump HeII bump WR stars WR stars few Myr old few Myr old Gonzalez Delgado et al. 1997, ApJ 483, 705
SB galaxies
8 SB galaxies = /- 0.1 dex = /- 0.2 dex [ 12 C / 13 C] < 10 enhancement, enrichement by SNII C mixed in the stellar interiors
see also Read & Stevens 2002, MNRAS, 335, L36
[FeII] : shock excited, type II SNe tracer Starburst99 models
Origlia & Oliva 2000, A&A, 357, 61
near IR dust optically thin near IR dust optically thin emission volume emission volume L dust (SB ) L dust (AGN ) / N L dust (SB ) L dust (AGN ) / N stellar clusters less efficient than stellar clusters less efficient than AGN in heating dust AGN in heating dust why in AGNs & not in SBs? T dust 1000 K R dust 1 pc
near IR dust optically thin emission volume near IR dust optically thin emission volume L dust (SB ) L dust (AGN ) / N L dust (SB ) L dust (AGN ) / N stellar clusters less efficient than AGN in heating dust stellar clusters less efficient than AGN in heating dust
: diagnostics : optical photometry & spectroscopy good for type II AGN not heavily obscured good for type II AGN not heavily obscured type I AGN hosts veiled by the AGN itself type I AGN hosts veiled by the AGN itself IR photometry & spectroscopy crucial to study obscured & type I AGN crucial to study obscured & type I AGN : surveys : optical: SDSS + small size samples of type II AGN IR: 2MASS + very small size samples of type I & II AGN
KV B U RGB AGB MS MS MS Renzini & Buzzoni 1986, in Spectral Evolution of Galaxies, 195 Maraston 1998, MNRAS 300, 872
Woosley & Weaver, 1995, ApJS, 101, 181