THE FORNAX DEEP SURVEY WITH VST. I. THE EXTENDED AND DIFFUSE STELLAR HALO OF NGC 1399 OUT TO 192 kpc

被引：104

作者：

Iodice, E. ^{[1
]}

Capaccioli, M. ^{[2
]}

Grado, A. ^{[1
]}

Limatola, L. ^{[1
]}

Spavone, M. ^{[1
]}

Napolitano, N. R. ^{[1
]}

Paolillo, M. ^{[2
,3
,4
]}

Peletier, R. F. ^{[5
]}

Cantiello, M. ^{[6
]}

Lisker, T. ^{[7
]}

Wittmann, C. ^{[7
]}

Venhola, A. ^{[5
,8
]}

Hilker, M. ^{[9
]}

D'Abrusco, R. ^{[2
]}

Pota, V. ^{[1
]}

Schipani, P. ^{[1
]}

机构：

[1] INAF, Astron Observ Capodimonte, Via Moiariello 16, I-80131 Naples, Italy

[2] Univ Naples Federico II, CU Monte St Angelo, Dip Fis Ettore Pancini, Via Cinthia, I-80126 Naples, Italy

[3] INFN, Sez Napoli, Via Cintia, I-80126 Naples, Italy

[4] Agenzia Spaziale Italiana Sci Data Ctr, Via Politecn Snc, I-00133 Rome, Italy

[5] Univ Groningen, Kapteyn Astron Inst, POB 72, NL-9700 Groningen, Netherlands

[6] INAF, Astron Observ Teramo, Via Maggini, I-64100 Teramo, Italy

[7] Heidelberg Univ, Zentrum Astron, Bergheimer Str 58, D-69115 Heidelberg, Germany

[8] Univ Oulu, Dept Phys, Div Astron, Oulu, Finland

[9] European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany

来源：

ASTROPHYSICAL JOURNAL | 2016年 / 820卷 / 01期

关键词：

galaxies: clusters: individual (Fornax); galaxies: elliptical and lenticular; cD; galaxies: halos; galaxies: photometry; EARLY-TYPE GALAXIES; LENS ACS SURVEY; SPECTROSCOPICALLY SELECTED SAMPLE; INTERACTION CROSS-SECTION; MATTER SELF-INTERACTIONS; MASS-DENSITY PROFILE; COLD DARK-MATTER; ABELL; 3827; CLUSTER; 1E-0657-56; ADAPTIVE OPTICS;

D O I：

10.3847/0004-637X/820/1/42

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We have started a new, deep multi-imaging survey of the Fornax cluster, dubbed the Fornax Deep Survey (FDS), at the VLT Survey Telescope (VST). In this paper we present the deep photometry inside two square degrees around the bright galaxy NGC 1399 in the core of the cluster. We found that the core of the Fornax cluster is characterized by a very extended and diffuse envelope surrounding the luminous galaxy NGC 1399: we map the surface brightness out to 33 arcmin (similar to 192 kpc) from the galaxy center and down to mu(g) similar to 31 mag arcsec(-2) in the g band. The deep photometry allows us to detect a faint stellar bridge in the intracluster region on the west side of NGC 1399 and toward NGC 1387. By analyzing the integrated colors of this feature, we argue that it could be due to the ongoing interaction between the two galaxies, where the outer envelope of NGC 1387 on its east side is stripped away. By fitting the light profile, we found that there exists a physical break radius in the total light distribution at R = 10 arcmin (similar to 58 kpc) that sets the transition region between the bright central galaxy and the outer exponential halo, and that the stellar halo contributes 60% of the total light of the galaxy (Section 3.5). We discuss the main implications of this work on the build-up of the stellar halo at the center of the Fornax cluster. By comparing with the numerical simulations of the stellar halo formation for the most massive bright cluster galaxies (i.e., 13 < logM(200)/M-circle dot < 14), we find that the observed stellar halo mass fraction is consistent with a halo formed through the multiple accretion of progenitors with stellar mass in the range 10(8)-10(11)M(circle dot). This might suggest that the halo of NGC 1399 has also gone through a major merging event. The absence of a significant number of luminous stellar streams and tidal tails out to 192 kpc suggests that the epoch of this strong interaction goes back to an early formation epoch. Therefore, different from the Virgo cluster, the extended stellar halo around NGC 1399 is characterized by a more diffuse and well-mixed component, including the intracluster light.

引用

页数：26