학술논문
Unraveling emission line galaxy conformity at z~1 with DESI early data
Document Type
Working Paper
Author
Yuan, Sihan; Wechsler, Risa H.; Wang, Yunchong; Reyes, Mithi A. C. de los; Myles, Justin; Rocher, Antoine; Hadzhiyska, Boryana; Aguilar, Jessica Nicole; Ahlen, Steven; Brooks, David; Claybaugh, Todd; Cole, Shaun; de la Macorra, Axel; Forero-Romero, Jaime E.; Gontcho, Satya Gontcho A; Guy, Julien; Honscheid, Klaus; Kisner, Theodore; Levi, Michael; Manera, Marc; Meisner, Aaron; Miquel, Ramon; Moustakas, John; Nie, Jundan; Palanque-Delabrouille, Nathalie; Poppett, Claire; Rezaie, Mehdi; Ross, Ashley J.; Rossi, Graziano; Sanchez, Eusebio; Schubnel, Michael; Seo, Hee- Jong; Tarlé, Gregory; Weaver, Benjamin Alan; Zhou, Zhimin
Source
Subject
Language
Abstract
Emission line galaxies (ELGs) are now the preeminent tracers of large-scale structure at z>0.8 due to their high density and strong emission lines, which enable accurate redshift measurements. However, relatively little is known about ELG evolution and the ELG-halo connection, exposing us to potential modeling systematics in cosmology inference using these sources. In this paper, we propose a physical picture of ELGs and improve ELG-halo connection modeling using a variety of observations and simulated galaxy models. We investigate DESI-selected ELGs in COSMOS data, and infer that ELGs are rapidly star-forming galaxies with a large fraction exhibiting disturbed morphology, implying that many of them are likely to be merger-driven starbursts. We further postulate that the tidal interactions from mergers lead to correlated star formation in central-satellite ELG pairs, a phenomenon dubbed "conformity." We argue for the need to include conformity in the ELG-halo connection using galaxy models such as IllustrisTNG, and by combining observations such as the DESI ELG auto-correlation, ELG cross-correlation with Luminous Red Galaxies (LRGs), and ELG-cluster cross-correlation. We also explore the origin of conformity using the UniverseMachine model and elucidate the difference between conformity and the well-known galaxy assembly bias effect.
Comment: 25 pages, 20 figures, submitted to MNRAS, comments welcome
Comment: 25 pages, 20 figures, submitted to MNRAS, comments welcome