红移z = 4.424的尘埃微央斯基射电源VLA J123642+621331的近红外相机和多目标光谱仪成像

NICMOS Imaging of the Dusty Microjansky Radio Source VLA J123642+621331 at z = 4.424.

作者信息

Waddington I, Windhorst RA, Cohen SH, Partridge RB, Spinrad H, Stern D

出版信息

Astrophys J. 1999 Dec 1;526(2):L77-L80. doi: 10.1086/312375.

Abstract

We present the discovery of a radio galaxy at a likely redshift of z=4.424 in one of the flanking fields of the Hubble Deep Field (HDF). Radio observations with the Very Large Array and MERLIN centered on the HDF yielded a complete sample of microjansky radio sources, of which about 20% have no optical counterpart to I</=25 mag. In this Letter, we address the possible nature of one of these sources through deep Hubble Space Telescope near-infrared camera and multiobject spectrometer (NICMOS) images in the F110W (J110) and F160W (H160) filters. VLA J123642+621331 has a single emission line at 6595 Å, which we identify with Lyalpha at z=4.424. We argue that this faint (H160=23.9 mag), compact (re approximately 0&farcs;2), red (I814-K=2.0) object is most likely a dusty, star-forming galaxy with an embedded active nucleus.

摘要

我们报告在哈勃深场（HDF）侧翼区域之一发现了一个红移可能为z = 4.424的射电星系。以HDF为中心利用甚大天线阵和MERLIN进行的射电观测产生了一个微焦耳射电源的完整样本，其中约20%在I≤25星等下没有光学对应体。在本信函中，我们通过哈勃空间望远镜近红外相机和多目标光谱仪（NICMOS）在F110W（J110）和F160W（H160）滤光片中拍摄的深场图像，探讨了其中一个源的可能性质。VLA J123642 + 621331在6595 Å处有一条发射线，我们将其确定为红移z = 4.424处的莱曼α线。我们认为这个暗弱（H160 = 23.9星等）、致密（半径约0&arcsec;2）、红色（I814 - K = 2.0）的天体很可能是一个带有嵌入活动核的尘埃形成恒星星系。