Surface thermophysical properties on the potentially hazardous asteroid (99942) Apophis

	Surface thermophysical properties on the potentially hazardous asteroid (99942) Apophis
	Yu Liangliang; Ji Jianghui; Ip Winghuen
刊名	Research in Astronomy and Astrophysics
	2017
卷号	17 期号:7 页码:70-1-70-10
英文摘要	We investigate the surface thermophysical properties (thermal emissivity, thermal inertia, roughness fraction and geometric albedo) of asteroid (99942) Apophis, using the currently available mid-infrared observations from CanariCam on Gran Telescopio CANARIAS and far-infrared data from PACS on Herschel, based on the Advanced ThermophysicalModel.We show that the thermal emissivity of Apophis should be wavelength dependent from 8.70 mum to 160 mum, and the maximum emissivity may appear around 20 mum, similar to that of Vesta. Moreover, we further derive the thermal inertia, roughness fraction, geometric albedo and effective diameter of Apophis within a possible 1sigma scale of Gamma= 100_(-52) ~(+100) Jm~(-2) s~(-0.5) K~(-1), f_r= 0.78~1.0, p_v= 0.286_(-0.026)~(+0.030) and D_(eff)=378_(-25)~(+19) m, and 3sigma scale of Gamma= 100_(-100)~(+240) Jm~(-2) s~(-0.5) K~(-1), f_r=0.2~1.0,p_v=0.286_(-0.029)~(+0.039) and D_(eff)=378_(-29)~(+27) m. The derived low thermal inertia but high roughness fraction may imply that Apophis could have regolith on its surface, where stronger space weathering but weaker regolith migration has happened in comparison with asteroid Itokawa. Our results show that small-size asteroids could also have fine regolith on the surface, and further infer that Apophis may have been delivered from the Main Belt by the Yarkovsky effect.
语种	英语
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/17499]
专题	中国科学院紫金山天文台
推荐引用方式 GB/T 7714	Yu Liangliang,Ji Jianghui,Ip Winghuen. Surface thermophysical properties on the potentially hazardous asteroid (99942) Apophis[J]. Research in Astronomy and Astrophysics,2017,17(7):70-1-70-10.
APA	Yu Liangliang,Ji Jianghui,&Ip Winghuen.(2017).Surface thermophysical properties on the potentially hazardous asteroid (99942) Apophis.Research in Astronomy and Astrophysics,17(7),70-1-70-10.
MLA	Yu Liangliang,et al."Surface thermophysical properties on the potentially hazardous asteroid (99942) Apophis".Research in Astronomy and Astrophysics 17.7(2017):70-1-70-10.