气候变化领域集成服务门户(CCPortal): A NuSTAR and XMM-Newton Study of the Two Most Actively Star-forming Green Pea Galaxies (SDSS J0749+3337 and SDSS J0822+2241)

CCPortal

DOI	10.3847/1538-4357/ab2bf6
	A NuSTAR and XMM-Newton Study of the Two Most Actively Star-forming Green Pea Galaxies (SDSS J0749+3337 and SDSS J0822+2241)
	Kawamuro T.; Ueda Y.; Ichikawa K.; Imanishi M.; Izumi T.; Tanimoto A.; Matsuoka K.
发表日期	2019
ISSN	0004637X
卷号	881 期号:1
英文摘要	We explore X-ray evidence for the presence of active galactic nuclei (AGNs) in the two most actively star-forming Green Pea galaxies (GPs), SDSS J0749+3337 and SDSS J0822+2241, which have star formation rates (SFRs) of 123 M o yr-1 and 78 M o yr-1, respectively. The GPs have red mid-infrared (MIR) spectral energy distributions and higher 22 μm luminosities than expected from a proxy of the SFR (Hα luminosity), consistent with hosting AGNs with 2-10 keV luminosities of ∼1044 erg s-1. We thus obtain and analyze the first hard (>10 keV) X-ray data observed with NuSTAR and archival XMM-Newton data below 10 keV. From the NuSTAR ≈20 ks data, however, we find no significant hard X-ray emission. By contrast, soft X-ray emission with 0.5-8 keV luminosities of ≈1042 erg s-1 is significantly detected in both targets, which can be explained only by star formation (SF). A possible reason for the lack of clear evidence is that a putative AGN torus absorbs most of the X-ray emission. Applying a smooth-density AGN torus model, we determine minimum hydrogen column densities along the equatorial plane (Neq H) consistent with the nondetection. The results indicate N eq H ≳ 2 × 1024 cm-2 for SDSS J0749+3337 and N eq H ≳ 5 × 10 24cm-2 for SDSS J0822+2241. Therefore, the GPs may host such heavily obscured AGNs. Otherwise, no AGN exists and the MIR emission is ascribed to SF. Active SF in low-mass galaxies is indeed suggested to reproduce red MIR colors. This would imply that diagnostics based on MIR photometry data alone may misidentify such galaxies as AGNs.. The American Astronomical Society. All rights reserved.
英文关键词	galaxies: active; galaxies: individual (SDSS J074936.77+333716.3 and SDSS J082247.66 +224144.0); infrared: galaxies; X-rays: galaxies
来源期刊	Astrophysical Journal
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/176373
作者单位	National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo, 181-8588, Japan; Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan; Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, 980-8578, Japan; Astronomical Institute, Tohoku University, Aramaki, Aoba-ku, Miyagi, Sendai, 980-8578, Japan; Dipartimento di Fisica e Astronomia, Universitá Degli Studi di Firenze, Via G. Sansone 1, Sesto Fiorentino, I-50019, Italy; INAF Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, Firenze, I-50125, Italy
推荐引用方式 GB/T 7714	Kawamuro T.,Ueda Y.,Ichikawa K.,et al. A NuSTAR and XMM-Newton Study of the Two Most Actively Star-forming Green Pea Galaxies (SDSS J0749+3337 and SDSS J0822+2241)[J],2019,881(1).
APA	Kawamuro T..,Ueda Y..,Ichikawa K..,Imanishi M..,Izumi T..,...&Matsuoka K..(2019).A NuSTAR and XMM-Newton Study of the Two Most Actively Star-forming Green Pea Galaxies (SDSS J0749+3337 and SDSS J0822+2241).Astrophysical Journal,881(1).
MLA	Kawamuro T.,et al."A NuSTAR and XMM-Newton Study of the Two Most Actively Star-forming Green Pea Galaxies (SDSS J0749+3337 and SDSS J0822+2241)".Astrophysical Journal 881.1(2019).