The Imprint of Clump Formation at High Redshift. II. The Chemistry of the Bulge

Victor P. Debattista, David J. Liddicott, Oscar A. Gonzalez, Leandro Beraldo e Silva, João A. S. Amarante, Ilin Lazar, Manuela Zoccali, Elena Valenti, Deanne B. Fisher, Tigran Khachaturyants, David L. Nidever, Thomas R. Quinn, Min Du, Susan Kassin

Research output: Contribution to journalArticlepeer-review

4 Downloads (Pure)


In Paper I, we showed that clumps in high-redshift galaxies, having a high star formation rate density (ΣSFR), produce disks with two tracks in the [Fe/H]–[α/Fe] chemical space, similar to that of the Milky Way’s (MW’s) thin+thick disks. Here we investigate the effect of clumps on the bulge’s chemistry. The chemistry of the MW’s bulge is comprised of a single track with two density peaks separated by a trough. We show that the bulge chemistry of an N-body + smoothed particle hydrodynamics clumpy simulation also has a single track. Star formation within the bulge is itself in the high-ΣSFR clumpy mode, which ensures that the bulge’s chemical track follows that of the thick disk at low [Fe/H] and then extends to high [Fe/H], where it peaks. The peak at low metallicity instead is comprised of a mixture of in situ stars and stars accreted via clumps. As a result, the trough between the peaks occurs at the end of the thick disk track. We find that the high-metallicity peak dominates near the mid-plane and declines in relative importance with height, as in the MW. The bulge is already rapidly rotating by the end of the clump epoch, with higher rotation at low [α/Fe]. Thus clumpy star formation is able to simultaneously explain the chemodynamic trends of the MW’s bulge, thin+thick disks, and the splash.
Original languageEnglish
Article number118
Pages (from-to)1-17
Number of pages17
JournalThe Astrophysical Journal
Issue number2
Publication statusPublished - 7 Apr 2023


  • 310
  • Galaxies and Cosmology


Dive into the research topics of 'The Imprint of Clump Formation at High Redshift. II. The Chemistry of the Bulge'. Together they form a unique fingerprint.

Cite this