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arXiv · 2606.10116

The Importance of Galaxy-Wide Star Formation in Driving Winds at z~1

Weichen Wang·Susan A. Kassin·S. M. Faber·David C. Koo·Timothy M. Heckman·Xinfeng Xu·Hassen M. Yesuf·Alexander de la Vega·Emily C. Cunningham·Puragra Guhathakurta·Yicheng Guo·Camilla Pacifici·John Pharo·Ying Qin
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Abstract

In this work, we study winds for a representative sample of 86 star-forming galaxies (SFGs) at z~1 with $M_\star = 10^{9.0}-10^{11.5} M_\odot$, by measuring the Mg II line profiles in deep Keck spectra. A total of 50 (58\%) are found to have winds. Unlike local starburst galaxies, the wind detection rate does not exhibit a threshold in star-formation rate (SFR) density $\Sigma_\mathrm{SFR}$ at 0.1 Msun/yr/kpc$^2$, but shows a gradual decline around this value. We find correlations between wind velocity $v_\mathrm{wind}$ and SFR, $\Sigma_\mathrm{SFR}$, and stellar mass, as per previous studies. Intriguingly, the z~1 SFGs appear to follow the same $v_\mathrm{wind}$-SFR relation as local starbursts. A combined fit gives: log $v_\mathrm{wind}$ = 0.16 log SFR + 2.4 (3-sigma significance). This unified relation spans over 4 dex in SFR and agrees with Illustris-TNG. No unified relation is found between $v_\mathrm{wind}$ and stellar mass, sSFR, or $\Sigma_\mathrm{SFR}$. This suggests winds might be most closely associated with SFR. We examine whether winds in z~1 SFGs are driven by their most compact star-forming regions. To do so, we consider whether the relation between $v_\mathrm{wind}$ and the $\Sigma_\mathrm{SFR}$ measured from only these regions is stronger than that for the galaxy-wide $\Sigma_\mathrm{SFR}$. We do not find a stronger correlation, suggesting that winds are most related to $\Sigma_\mathrm{SFR}$ of the entire galaxy. Collectively, these findings suggest a picture in which galaxy-wide star formation plays an important role in driving winds at z~1. Wind bubbles from all star-forming regions could combine momentum and help lift their entrained gas out of the galaxy.

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Weichen Wang, Susan A. Kassin, S. M. Faber, David C. Koo, Timothy M. Heckman, Xinfeng Xu, Hassen M. Yesuf, Alexander de la Vega, Emily C. Cunningham, Puragra Guhathakurta, Yicheng Guo, Camilla Pacifici, John Pharo, Ying Qin. 2026-06-08. The Importance of Galaxy-Wide Star Formation in Driving Winds at z~1. https://arxiv.org/abs/2606.10116

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