Surface brightness fluctuation spectrum: a new probe of evolved stars in unresolved stellar populations

Journal
Date Issued
2018
Author(s)
Mitzkus, Martin
•
Walcher, C. Jakob
•
Roth, Martin M.
•
Coelho, Paula R. T.
•
Cioni, Maria-Rosa L.
•
•
Rejkuba, Marina
DOI
Abstract
The surface brightness fluctuation (SBF) method measures spatial fluctuations due to the most luminous stars in a galaxy. Besides being useful for distance measurements, it also provides diagnostic power to investigate the contribution of the brightest stars to the underlying unresolved stellar population. We apply the SBF technique to every wavelength layer in integral field spectroscopy data obtained with the MUSE instrument. This yields the first SBF spectrum of a galaxy. SBF spectra combine the sensitivity of SBF to luminous stars with the physical information content of spectra. We show that the SBF spectrum of the S0 galaxy NGC 5102 is dominated by spectra of M-type giants (red giant branch, asymptotic giant branch, and red supergiant stars). We build the first stellar population synthesis tool that predicts SBF spectra. Through comparison of integrated spectra from our new tool with published model spectra, we confirm that it is mathematically correct. We use the integrated spectrum and a bootstrap method to derive an ensemble of (degenerate) star formation histories of NGC 5102. We compute a model SBF spectrum for each star formation history. Given that some models do not reproduce the observed SBF spectrum well, we are able to obtain additional constraints on the star formation history, leading to marginally reduced uncertainties on the mean age and metallicity. This result is confirmed by modelling mock spectra with different star formation histories.
Volume
480
Issue
1
Start page
629
Uri
Url
Issn Identifier
0035-8711
Ads BibCode
2018MNRAS.480..629M
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

28181-Mitzkus_2018_MNRAS_480_P02.pdf

Description
Miur
Size

4.65 MB

Format

Adobe PDF

Checksum (MD5)

02b90dd876abb843b704116ba2ba9ba2

Loading...
Thumbnail Image
Name

Mitzkus_2018_MNRAS_480.pdf

Description
Pdf editoriale
Size

12.72 MB

Format

Adobe PDF

Checksum (MD5)

013fde0a65c79d52c734840e4e7f69bf