搜索结果: 1-15 共查到“天文学 HI”相关记录27条 . 查询时间(0.062 秒)
中国科学院上海天文台科研人员发布最新HI 21-cm吸收观测结果（图）
中国科学院上海天文台 HI 21-cm 吸收 观测结果
2020/12/14
氢（HI）是宇宙中最丰富的元素，它也是星系中形成恒星的重要原料。观测发现，高红移【1】天体系统的恒星形成率较高，因此预计高红移星系中冷氢气的相对含量（丰度）较高，但实际观测却发现高红移星系中探测到HI 21cm吸收线的比例非常低【2】。针对这一差异，有研究认为，来自星系中心的活动星系核的强烈紫外线辐射可能会电离周围的星际介质，降低了中性气体含量，从而降低了HI吸收强度，以致于探测不到。研究人员提出...
First results from long-term,hi-res tracking of eruptions on Jupiter's moon Io
long-term hi-res tracking eruptions Jupiter moon Io
2016/11/4
Jupiter’s moon Io continues to be the most volcanically active body in the solar system, as documented by the longest series of frequent, high-resolution observations of the moon’s thermal emission ev...
The large asymmetric HI envelope of the isolated galaxy NGC 864 (CIG 96)
NGC 864 (CIG 96) maximum
2014/12/24
We present an HI synthesis imaging study of NGC 864 (CIG 96), a spiral galaxy well isolated from similarly sized companions, yet presenting an intriguing asymmetry in its integral HI spectrum. The asy...
In this contribution, we present some preliminary observational results from the completed ultra-deep survey of 21cm emission from neutral hydrogen at redshifts z=0.164-0.224 with the Westerbork Synth...
Setting the Normalcy Level of HI Properties in Isolated Galaxies
atomic gas local Universe
2014/12/20
Studying the atomic gas (HI) properties of the most isolated galaxies is essential to quantify the effect that the environment exerts on this sensitive component of the interstellar medium. We observe...
星系中的HI空洞及其形成机制
星际介质 HI壳层 HI空洞 形成机制
2012/9/12
旋涡星系和不规则星系中存在众多的H工空洞已是不争的事实，它们形态各异、大小不一、物理特征差别明显。人们不仅对若干近距星系中的H工空洞做了较为细致的观测研究，而且随着观测资料的积累，相关统计研究亦渐趋深入。迄今已就H工空洞的形成机制提出了多种理论模型，但对这一问题的认识尚未完全取得一致。
An HI column density threshold for cold gas formation in the Galaxy
column density threshold cold gas formation Galaxy
2011/9/28
We report the discovery of a threshold in the HI column density of Galactic gas clouds below which the formation of the cold phase of HI is inhibited. This threshold is at $N_{HI} = 2 \times 10^{20}$ ...
HALOGAS: HI Observations and Modeling of the Nearby Edge-on Spiral Galaxy NGC 4244
HALOGAS: HI Observations Modeling Nearby Edge-on Spiral
2011/10/12
We present 21-cm observations and models of the HI kinematics and distribution of NGC 4244, a nearby edge-on Scd galaxy observed as part of the Westerbork Hydrogen Accretion in LOcal GAlaxieS (HALOGAS...
We present optical (UBVJ), ultraviolet (FUV, NUV), and high resolution atomic hydrogen (HI) observations of the nearby blue compact dwarf (BCD), VII Zw 403. We find that VII Zw 403 has a relatively hi...
Current studies of the peculiar velocity flow field in the Local Universe are limited by the lack of detection of galaxies behind the Milky Way. The contribution of the largely unknown mass distributi...
The AMIGA sample of isolated galaxies: VIII. The rate of asymmetric HI profiles in spiral galaxies
galaxies: evolution – galaxies: interactions – galaxies: ISM – surveys – HI : galaxies
2011/9/27
(abridged) Measures of the HI properties of a galaxy are among the most sensitive interaction diagnostic at our disposal. We report here on a study of HI profile asymmetries (e.g., lopsidedness) in a ...
GSH 91.5+2-114: A large HI shell in the outer part of the Galaxy
ISM bubbles — ISM kinematics and dynamics —ISM structure —supernova remnants
2010/11/10
GSH 91.5+ 2− 114 is a large HI shell located in the outer Galaxy at a kinematic distance of about 15 kpc. It was first identified in the Canadian Galactic Plane Survey (CGPS) by Pineault et al.
Deep 21-cm HI Observations at z~0.1: The Precursor to the Arecibo Ultra Deep Survey
cosmology observations galaxies evolution radio lines galaxies
2010/11/10
The \ALFA Ultra Deep Survey" (AUDS) is an ongoing 21-cm spectral survey with the Arecibo 305m telescope. AUDS will be the most sensitive blind survey undertaken with Arecibo's 300 MHz Mock spectromete...
A High-Resolution Survey of HI Absorption toward the Central 200 pc of the Galactic Center
High-Resolution Survey Galactic Center
2010/11/10
We present an HI absorption survey of the central 250 pc of the Galaxy. Very Large Array (VLA) observations were made at 21 cm in the DnC and CnB con gurations and have a resolution of 15"(0.6 pc at ...
We studied the global distribution and kinematics of the extra-planar neutral gas in the Milky Way.