Red Supergiants as Extragalactic Abundance Probes: Establishing the J-Band Technique Zach Gazak Rolf Kudritzki (chair), Josh Barnes, Fabio Bresolin, Ben Davies, Lisa Kewley, John Learned, John Rayner

Red Supergiants as Extragalactic Abundance Probes: Establishing the J-Band Technique Rogelio Bernal Andreo (DeepSkyColors.com) α Orionis (Betelgeuse)

Metallicity gradients of star forming galaxies: Extragalactic Chemical Abundances Key targets for understanding galaxy formation and evolution Important input for modeling galaxy evolution Mass - Metallicity and Mass - Gradient relationship M31 Jerry Lodriguss M33 Ken Crawford M33 Ken Crawford M81 Giovanni Benintende NGC 2403 Subaru

Metallicity gradients of star forming galaxies: Extragalactic Chemical Abundances M33 Ken Crawford Typically measured using highly uncertain “strong line” methods of collisional lines in H II regions: Problems with these methods include: I. Troublesome calibration II. Abundance discrepancies III. Line saturation degeneracies

Collisional line methods from H II regions I: Troublesome Calibration Results depend heavily on choice of calibration NGC 300 (ESO)

Collisional line methods from H II regions I: Troublesome Calibration Results depend heavily on choice of calibration NGC 300 (ESO) Bresolin et al. 2009

Collisional line methods from H II regions I: Troublesome Calibration Results depend heavily on choice of calibration NGC 300 (ESO) Kewley & Ellison 2008

Collisional metallicities 0.2 to 0.4 dex lower than recombination measurements. II: Abundance Discrepancy Factor Simon-Diaz & Stasinska 2010 Dust composition

Collisional metallicities 0.2 to 0.4 dex lower than recombination measurements. II: Abundance Discrepancy Factor Simon-Diaz & Stasinska 2010 Peimbert et al Dust composition

Degeneracy at over ~0.5 solar metallicity III: Line Saturation Stasinska 2010 [OIII] and [NII][NII] only

Significant Discrepancies Stasinska 2010 [OIII] and [NII] [NII] only Simon-Diaz & Stasinska 2010 M33: U et al A and B Supergiants

Significant Discrepancies Stasinska 2010 [OIII] and [NII] [NII] only Simon-Diaz & Stasinska 2010 M33: U et al A and B Supergiants + HII Regions

Stars drive chemical enrichment Evolution of galaxies Abundance pattern gradients Interstellar extinction Distances Quantitative Spectroscopy of Stars

8 < M init < 35 M sun Red Supergiants B8-A4 K–M M J -8 to -11

Cool: T eff < 4500 K Inflated: R on AU scales Convection + Mass Loss Red Supergiants ESO Betelgeuse ESO & P. Kervella

Historically, high resolution (R~20,000) required. Unrealistic extragalactic integration times! Davies, Kudritzki & Figer 2010: We can use R~3000 in J band, log[Z] to 0.1 dex Spectroscopy of RSGs

Peak RSG flux and strong, well separated lines RSGs in the J Band 3500 K J band

Peak RSG flux and strong, well separated lines RSGs in the J Band 3500 K J band R~2500 SpeX (Rayner et al. 2009) HD 39801

MARCS model grid: Spherical symmetry, LTE RSGs in the J Band R~2500 SpeX (Rayner et al. 2009) HD 39801

MARCS model grid: Spherical symmetry, LTE RSGs in the J Band R~2500 SpeX (Rayner et al. 2009) HD Teff: /- 220 (3710) log[Z]: / (0.19 +/- 0.21)

Finding RSGs Image Courtesy of Mike Bessell LMC Ben Davies

M33

Thesis work: I. The Milky Way II. Local Group Galaxies III. Beyond the Local Group Solar metallicity Perseus OB1 RSGs M31 (Milky Way analog) M33 (sub-solar metallicities) M81 (super solar metallicities) NGC2403 (sub-solar metallicities) Super Star Clusters (SSCs)

I. Solar Neighborhood: Per OB RSGs

I. Solar Neighborhood: Per OB-1 Observe full RSG population at high and low resolution Compare and calibrate high-R v. low-R methods Calibrate to well established BSG techniques J, H at R~20,000: IRCS on Subaru (1 night) R~ 2,500: SpeX on IRTF (1 night) MARCS model grid Develop analysis techniques Collaborate with Urbaneja, Kudritzki: spectra of all known BSGs in Per OB1

I. Solar Neighborhood: Per OB-1 Critical dataset for this work and into the future Test and calibrate new future RSG atmosphere codes

II. Galactic Neighborhood: M31, M33 M31 Jerry Lodriguss M33 Ken Crawford Metallicity gradients of Local Group galaxies using RSGs

Milky Way analog Very little spectroscopic information over the radial gradient. 1000s of RSGs II. Galactic Neighborhood: M31, M33 M31 Jerry Lodriguss 2 nights with MOSFIRE on Keck I: Full coverage of radial metallicity gradient with detailed information on α/Fe element ratios.

II. Galactic Neighborhood: M31, M33 M33 Ken Crawford 1 night with MOSFIRE on Keck I: Cover radial gradient with brightest RSGs, allowing a critical test of conflicting results between HII and BSGs. M33: U et al A and B Supergiants + HII Regions

Abundance gradient of M81 or NGC 2403 III: Beyond the Local Group M81 Giovanni Benintende NGC 2403 Subaru

III: Beyond the Local Group M81 Giovanni Benintende 4 Mpc Indications of super-solar central metallicity and shallow gradient 1000s of RSGs 3 nights with MOSFIRE on Keck I: Mass-metallicity relationship from RSGs (with LG work) Spiral galaxy metallicity gradients independent of mass if considered on a dimensionless length scale?

10 5 M sun with ~100 RSGs: reach 10x distances IIIb: Super Star Clusters M82: McCrady & Graham 2007

10 5 M sun with ~100 RSGs: reach 10x distances IIIb: Super Star Clusters Perseus OB1 work will allow a critical test Proceed with additional observations if successful Promising agreement with M51 SSC photometry from Nate Bastian

RSGs with Extremely Large Telescopes Evans et al Limiting m J ~23 means RSGs beyond Virgo Cluster

RSGs with Extremely Large Telescopes Evans et al Limiting m J ~23 means RSGs beyond Virgo Cluster

RSGs with Extremely Large Telescopes Excellent recovery of metallicity (Evans et al. 2010)

Center of Virgo Cluster Gunter Kerschhuber

Thesis Timeline MOSFIRE backup instrument is FMOS on Subaru