The potential of JWST to Measure the Mass-Loss Return from Stars to Galaxies

Acknowledgements: Funding from NASA-ADAP, Herschel/HERITAGE, and NAG5 grants is acknowledged.

M. Meixner (STScI), B. Sargent (STScI, RIT), D. Riebel (JHU), S. Srinivasan (IAP),

& M. Otsuka (ASIAA)

Abstract

The JWST telescope will have the sensitivity and spectral resolving power to analyze the mass-loss return from stars to galaxies in the Local Volume of galaxies. For example, color magnitude diagrams from photometric imaging with NIRCam and MIRI can be used to identify dusty evolved stars which can then be compared to precomputed models such as GRAMS to derive dust mass loss returns. Spectroscopy of sources with MIRI or NIRSpec can help identify the dust species and correlate with type of star and environment. Time monitoring of recent supernova explosions can be performed to look for the signatures of dust production. Measurements of elemental abundances and dust content in planetary nebulae located in nearby galaxies can support studies of dust production vs. metal abundance in stars.

Conclusions:JWST and MIRI in particular will be capable of directly observing and quantifying the mass-loss return from stars to galaxies by measuring the dust emission from AGB stars, RSG stars, planetary nebulae and supernovae. Model grids such as GRAMS will be important to make the analysis of these data efficient; allowing for statistical analysis. We show that JWST/MIRI will be able probe this mass loss return in nearby galaxies, like the Andromeda Galaxy (M31), out to the local volume (10 Mpc) via resolved stellar population analysis. Thus, through application of JWST to this problem, we can really understand the epoch of dust formation in the Universe: when did dust first form in the Universe and how has it affected the evolution of galaxies and our observations of the Universe.

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PLANETARY NEBULAE: O-rich planetary nebula SMP LMC 81 in the LMC and also scaled down if it were in N6822. For comparison, the expected sensitivities of MIRI imaging and spectroscopy modes are also plotted, for various S/N ratios and integration times. MIRI will enable detailed studies of the very final stages of stellar evolution for many nearby galaxies.

A [8.0]-[24] CMD from SAGE observations. Black points are the whole SAGE catalog. The colored points have spectra from Spitzer IRS SAGE-Spec project (Kemper et al. 2010): red (new observations) and blue (reprocessed archival observations). The thin line drawn at the bottom of the plot labeled “S/N~10, 2hrs” indicates the [8.0] magnitude at which MIRI could obtain a spectrum with a continuum S/N of about 10 for a 2 hour integration. MIRI will therefore be able to obtain high quality mid-infrared spectra of almost any evolved star in the LMC.

ASYMPTOTIC GIANT BRANCH AND RED SUPERGIANT STARS: The SAGE program for the LMC obtained Color-Magnitude Diagrams (CMDs) like the one at left (e.g., Srinivasan et al 2009). RSGs are red points, O-rich AGBs are blue, C-rich AGBs are purple, and extreme AGBs best fit by C-rich (O-rich) models are green (black). By convolving preliminary JWST-MIRI filter transmission curves with best-fit models of AGB and RSG stars, one obtains synthetic fluxes for MIRI bands. The fluxes of models that were best-fit to LMC SAGE observations of evolved stars were then scaled for evolved stars in M31 being at 780 pc (Peacock et al 2011) for the CMD at center. The Color-Color Diagram (CCD) at right simulates how MIRI might distinguish between O-rich and C-rich evolved stars.

SAGE-LMC CMD Simulated MIRI CMD for M31

Simulated MIRI CCD

SUPERNOVAE: The predicted SEDs of H-rich SNe in d=20/40/80 Mpc, after 690 days explosion in d = 20, 40, and 80 Mpc. The SED of SN2004et in NGC6946 at the same epoch (Fabbri et al. 2011) is used as the template.  When we select MIRI imaging mode, we would be able to detect SNe within 80 Mpc with the MIRI filters <18 microns. For example, in 2009, 33 H-rich SNe were discovered. Of them, 26 objects were in galaxies within 80 Mpc.

This Spitzer IRAC [8] vs IRAC [8] - MIPS [24] micron color-magnitude diagram shows all the SAGE epoch 1 catalog point sources in grey (Meixner et al. 2006). Over-plotted are SAGE sources with candidate classifications as shown in the legend. The dashed line shows the final expected sensitivity limit. The red line shows the anticipated limit for MIRI/JWST using the same total integration time (~48 seconds) per pointing & band as Spitzer for LMC targets (its off the bottom). The black solid lines show the brightness cutoff that would be probed in such an integration for a galaxy at a distance of ~1 or 10 Mpc