The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER). II. The Spatially Resolved Recent Star Formation History of M33

Margaret Lazzarini, Benjamin F. Williams, Meredith J. Durbin, Julianne J. Dalcanton, Adam Smercina, Eric F. Bell, Yumi Choi, Andrew Dolphin, Karoline Gilbert, Puragra Guhathakurta, Erik Rosolowsky, Evan Skillman, O. Grace Telford, Daniel Weisz

Research output: Contribution to journalArticlepeer-review

Abstract

We measure the spatially resolved recent star formation history (SFH) of M33 using optical images taken with the Hubble Space Telescope as part of the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) survey. The area covered by the observations used in this analysis covers a de-projected area of ∼38 kpc2 and extends to ∼3.5 and ∼2 kpc from the center of M33 along the major and semimajor axes, respectively. We divide the PHATTER optical survey into 2005 regions that measure 24 arcsec, ∼100 pc, on a side and fit color-magnitude diagrams for each region individually to measure the spatially resolved SFH of M33 within the PHATTER footprint. There are significant fluctuations in the SFH on small spatial scales and also galaxy-wide scales that we measure back to about 630 Myr ago. We observe a more flocculent spiral structure in stellar populations younger than about 80 Myr, while the structure of the older stellar populations is dominated by two spiral arms. We also observe a bar in the center of M33, which dominates at ages older than about 80 Myr. Finally, we find that the mean star formation rate (SFR) over the last 100 Myr within the PHATTER footprint is 0.32 ± 0.02 M yr−1. We measure a current SFR (over the last 10 Myr) of 0.20 ± 0.03 M yr−1. This SFR is slightly higher than previous measurements from broadband estimates, when scaled to account for the fraction of the D25 area covered by the PHATTER survey footprint.

Original languageEnglish (US)
Article number76
JournalAstrophysical Journal
Volume934
Issue number1
DOIs
StatePublished - Jul 1 2022

Bibliographical note

Funding Information:
We thank Leo Girardi for his thoughtful comments on this paper. Support for this work was provided by NASA through grant No. GO-14610 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555. M.L. was supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-2102721 during a portion of this work.

Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.

Fingerprint

Dive into the research topics of 'The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER). II. The Spatially Resolved Recent Star Formation History of M33'. Together they form a unique fingerprint.

Cite this