Less than the sum of its parts: the dust-corrected H alpha luminosity of star-forming galaxies explored at different spatial resolutions with MaNGA and MUSE

Autor(es):Mostrar menos -

Asari, N. Vale ^{[1, 2]} ; Wild, V ^[1] ; de Amorim, A. L. ^[2] ; Werle, A. ^{[3, 4, 2]} ; Zheng, Y. ^[1] ; Kennicutt, R. ^{[5, 6]} ; Johnson, B. D. ^[7] ; Galametz, M. ^[8] ; Pellegrini, E. W. ^[9] ; Klessen, R. S. ^{[9, 10]} ; Reissl, S. ^[9] ; Glover, S. C. O. ^[9] ; Rahner, D. ^[9]

Afiliação do(s) autor(es)

^[1] Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife - Scotland

^[2] Univ Fed Santa Catarina, Dept Fis CFM, CP 476, BR-88040900 Florianopolis, SC - Brazil

^[3] INAF Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua - Italy

^[4] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, R Matao 1226, BR-05508090 Sao Paulo - Brazil

^[5] Texas A&M Univ, Dept Phys & Astron, College Stn, TX 77843 - USA

^[6] Univ Arizona, Steward Observ, 933 N Cherry Ave, Lircson, AZ 85721 - USA

^[7] Harvard Univ, Dept Astron, Cambridge, MA 02138 - USA

^[8] Univ Paris Diderot, Univ Paris Saclay, Sorbonne Paris Cite, AIM, CEA, CNRS, F-91191 Gif Sur Yvette - France

^[9] Heidelberg Univ, Inst Theoret Astrophys, Zentrum Astron, Albert Ueberle Str 2, D-69120 Heidelberg - Germany

^[10] Heidelberg Univ, Interdisziplinares Zentrum Wissensch Rechnen, Neuenheimer Feld 205, D-69120 Heidelberg - Germany

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 498, n. 3, p. 4205-4221, NOV 2020.
• Citações Web of Science: 0

Resumo

The H alpha and H beta emission-line luminosities measured in a single integrated spectrum are affected in non-trivial ways by pointto-point variations in dust attenuation in a galaxy. This work investigates the impact of this variation when estimating global H alpha luminosities corrected for the presence of dust by a global Balmer decrement. Analytical arguments show that the dust-corrected H alpha luminosity is always underestimated when using the global H alpha/H beta flux ratio to correct for dust attenuation. We measure this effect on 156 face-on star-forming galaxies from the Mapping Nearby Galaxies at APO (MaNGA) survey. At 1-2 kpc spatial resolution, the effect is small but systematic, with the integrated dust-corrected H alpha luminosity underestimated by 2-4 per cent (and typically not more than by 10 per cent), and depends on the specific star formation rate of the galaxy. Given the spatial resolution of MaNGA, these are lower limits for the effect. From Multi Unit Spectroscopic Explorer (MUSE) observations of NGC628 with a resolution of 36 pc, we find the discrepancy between the globally and the point-by-point dust-corrected H alpha luminosity to be 14 +/- 1 per cent, which may still underestimate the true effect. We use toy models and simulations to show that the true difference depends strongly on the spatial variance of the H alpha/H beta flux ratio, and on the slope of the relation between H alpha luminosity and dust attenuation within a galaxy. Larger samples of higher spatial resolution observations are required to quantify the dependence of this effect as a function of galaxy properties. (AU)

• Processo FAPESP: 19/01768-6 - Estrutura em larga escala no universo local com o levantamento de dados S-PLUS
• Beneficiário: Ariel Werle
• Modalidade de apoio: Bolsas no Brasil - Programa Capacitação - Treinamento Técnico