A near-infrared excess in the continuum of high-redshift galaxies: a tracer of star formation and circumstellar disks?

Par Conseil national de recherches du Canada

Téléchargement	Voir le manuscrit accepté : A near-infrared excess in the continuum of high-redshift galaxies: a tracer of star formation and circumstellar disks? (PDF, 1.7 Mio)
DOI	Trouver le DOI : https://doi.org/10.1088/0004-637X/706/2/1020
Auteur	Rechercher : Mentuch, Erin; Rechercher : Abraham, Roberto G.; Rechercher : Glazebrook, Karl; Rechercher : McCarthy, Patrick J.; Rechercher : Yan, Haojing; Rechercher : O'Donnell, Daniel V.; Rechercher : Le Borgne, Damien; Rechercher : Savaglio, Sandra; Rechercher : Crampton, David¹; Rechercher : Murowinski, Richard¹; Rechercher : Juneau, Stéphanie; Rechercher : Carlberg, R. G.; Rechercher : Jørgensen, Inger; Rechercher : Roth, Kathy; Rechercher : Chen, Hsiao-Wen; Rechercher : Marzke, Ronald O.
Affiliation du nom	Conseil national de recherches du Canada. Institut Herzberg d'astrophysique du CNRC
Format	Texte, Article
Sujet	circumstellar matter; galaxies: evolution; galaxies: stellar content; infrared: galaxies; infrared: stars; planetary systems: protoplanetary disks
Résumé	A broad continuum excess in the near-infrared, peaking in the rest frame at 2-5 μm, is detected in a spectroscopic sample of 88 galaxies at 0.5 < z < 2.0 taken from the Gemini Deep Deep Survey. Line emission from polycyclic aromatic hydrocarbons (PAHs) at 3.3 μm alone cannot explain the excess, which can be fit by a spectral component consisting of a template of PAH emission lines superposed on a modified blackbody of temperature T ~ 850 K. The luminosity of this near-infrared excess emission at 3 μm is found to be correlated with the star formation rate of the galaxy. The origin of the near-infrared excess is explored by examining similar excesses observed locally in massive star-forming regions, reflection and planetary nebulae, post-asymptotic giant branch stars, and in the galactic cirrus. We also consider the potential contribution from dust heated around low-luminosity active galactic nuclei. We conclude that the most likely explanation for the 2-5 μm excess is the contribution from circumstellar disks around massive young stellar objects seen in the integrated light of high-redshift galaxies. Assuming circumstellar disks extend down to lower masses, as they do in our own Galaxy, the excess emission presents us with an exciting opportunity to measure the formation rate of planetary systems at cosmic epochs before our own solar system formed.
Date de publication	2009
Maison d’édition	American Astronomical Society IOP Publishing
Dans	The Astrophysical Journal 706 : 1020–1035.
Langue	anglais
Publications évaluées par des pairs	Oui
Numéro NPARC	21275914
Exporter la notice	Exporter en format RIS
Signaler une correction	Signaler une correction (s'ouvre dans un nouvel onglet)
Identificateur de l’enregistrement	6ec21bd3-be8f-4a20-80d9-56b7dbc759f0
Enregistrement créé	2015-08-04
Enregistrement modifié	2020-06-04

Signaler un problème ou une erreur sur cette page

Date de modification :: 2023-10-04