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When Did the Hubble Sequence Appear?: Morphology, Color, and Number-Density Evolution of the Galaxies in the Hubble Deep Field North
Yamada, Toru; Kajisawa, Masaru
Using the HST WFPC2/NICMOS archival data of the Hubble Deep Field North, we constructed a nearly complete sample of the MV < -20 (~ L* + 1) galaxies to z = 2, and investigate when the Hubble sequence appeared, namely, the evolution of the morphology, colors, and the comoving number density of the sample. Even if taking int…
The Spectral Energy Distributions of Blazars and the Connections among XBLs, RBLs, and OVV Quasars
Dai, Benzhong; Ma, Li; Xie, Guangzhong +2 more
In this paper, we introduce two composite spectral indices, αxox=αox-αx and αoro=αor-αo. In the composite color-color (αxoxαoro) diagram, there are three regions: (1) For XBLs and XBL-like RBLs, the values of αxox is in the range of -1.0 -0.0; (2) Fo…
Hipparcos Proper-Motion System with Respect to SPM 2.0
Zhu, Zi
On the basis of Hipparcos data, whose system is believed to be quasi-inertial to within +/-0.25 mas yr-1 and to represent an internally consistent reference frame, we carried out an analysis of the SPM 2.0 proper-motion system. Comparing the Hipparcos proper motions with those of the SPM 2.0 Catalog, which provides absolute proper motio…
NIR Narrow- and Broad-Band Study of the SSA 22 Field
Tamura, Naoyuki; Ohta, Kouji; Takata, Tadafumi +4 more
Deep narrow- and broad-band near-infrared imaging observations of the central 2'×2' region of the SSA 22 field were made with the near-infrared camera (CISCO) attached to the Subaru Telescope. Using a narrow-band filter centered at 2.033µm, [O III] λ5007 emitters at z ~ 3.06 +/- 0.02 were searched to examine star-forming activities in an ove…