MIGHTEE-H i: the H i size–mass relation over the last billion years. Issue 2 (14th March 2022)

• Record Type: Journal Article
• Authors: Rajohnson, Sambatriniaina H A; Frank, Bradley S; Ponomareva, Anastasia A; Maddox, Natasha; Kraan-Korteweg, Renée C; Jarvis, Matt J; Adams, Elizabeth A K; Oosterloo, Tom; Baes, Maarten; Spekkens, Kristine; Adams, Nathan J; Glowacki, Marcin; Kurapati, Sushma; Prandoni, Isabella; Heywood, Ian; Collier, Jordan D; Sekhar, Srikrishna; Taylor, Russ
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 512:Issue 2(2022)
• Page Start: 2697
• Page End: 2706
• Publication Date: 2022-03-14
• Subjects: surveys -- galaxies: evolution -- galaxies: kinematics and dynamics -- radio lines: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac693
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present the observed H i size–mass relation of 204 galaxies from the MIGHTEE Survey Early Science data. The high sensitivity of MeerKAT allows us to detect galaxies spanning more than 4 orders of magnitude in H i mass, ranging from dwarf galaxies to massive spirals, and including all morphological types. This is the first time the relation has been explored on a blind homogeneous data set that extends over a previously unexplored redshift range of 0 < z < 0.084, i.e. a period of around one billion years in cosmic time. The sample follows the same tight logarithmic relation derived from previous work, between the diameter ($D_{\rm H\, \small {\rm I}}$ ) and the mass ($M_{\rm H\, \small {\rm I}}$ ) of H i discs. We measure a slope of 0.501 ± 0.008, an intercept of $-3.252^{+0.073}_{-0.074}$, and an observed scatter of 0.057 dex. For the first time, we quantify the intrinsic scatter of 0.054 ± 0.003 dex (${\sim } 10 {{\ \rm per\ cent}}$ ), which provides a constraint for cosmological simulations of galaxy formation and evolution. We derive the relation as a function of galaxy type and find that their intrinsic scatters and slopes are consistent within the errors. We also calculate the $D_{\rm H\, \small {\rm I}}{ \!-\! }M_{\rm H\, \small {\rm I}}$ relation for two redshift bins and do not find any evidence for evolution with redshift. These results suggest that over a period of one billion years in look-back time, galaxy discs have not undergone significant evolution in their gas distribution and mean surface mass density, indicating a lack of dependence on both morphological type and redshift.