Language:
English
繁體中文
Help
回圖書館首頁
手機版館藏查詢
Login
Back
Switch To:
Labeled
|
MARC Mode
|
ISBD
An Exploration of Inter-Stellar Gas ...
~
Pavesi, Riccardo.
Linked to FindBook
Google Book
Amazon
博客來
An Exploration of Inter-Stellar Gas and Its Role in Galaxy Assembly over Cosmic Time.
Record Type:
Electronic resources : Monograph/item
Title/Author:
An Exploration of Inter-Stellar Gas and Its Role in Galaxy Assembly over Cosmic Time./
Author:
Pavesi, Riccardo.
Published:
Ann Arbor : ProQuest Dissertations & Theses, : 2019,
Description:
409 p.
Notes:
Source: Dissertations Abstracts International, Volume: 80-12, Section: B.
Contained By:
Dissertations Abstracts International80-12B.
Subject:
Astrophysics. -
Online resource:
http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=13883666
ISBN:
9781392252406
An Exploration of Inter-Stellar Gas and Its Role in Galaxy Assembly over Cosmic Time.
Pavesi, Riccardo.
An Exploration of Inter-Stellar Gas and Its Role in Galaxy Assembly over Cosmic Time.
- Ann Arbor : ProQuest Dissertations & Theses, 2019 - 409 p.
Source: Dissertations Abstracts International, Volume: 80-12, Section: B.
Thesis (Ph.D.)--Cornell University, 2019.
This item must not be sold to any third party vendors.
The key physical processes driving galaxy formation and evolution are controlled by gas and, in particular, the process of star formation from cold, dense gas is not well understood since it depends upon the gas cooling ability, its dynamical state and complex feedback processes. Galaxies were observed to form stars much more rapidly in the past (~10-11 billion years ago), which may be due to larger gas reservoirs or more efficient star formation processes. While previous studies have identified large molecular gas reservoirs in a few pre-selected star-forming galaxies, an unbiased survey for molecular gas is necessary to provide robust statistical constraints to the gas content of galaxies at the peak epoch of cosmic star formation. Taking advantage of the improved frequency coverage, sensitivity and bandwidth of the upgraded Very Large Array we have carried out the first unbiased survey by performing a deep-field blind search for CO(1-0) line emission at z~2-3 and CO(2-1) line emission at z~5-7, targeting CO(1-0) which is the most commonly used tracer of the cold, dense molecular gas which fuels star formation. Having detected the first CO(1-0)-selected galaxies at high redshift, we have used their luminosity and abundance to provide robust statistical constraints to the CO luminosity function at z~2-3, finding conclusive evidence for a much higher gas mass content relative to galaxies in the local Universe. This finding suggested that evolution in the mechanisms of star formation may not be the dominant contribution to the high observed star formation rates, but rather large amounts of available cold gas. In order to explore how this finding may apply to even higher redshift, we have also achieved the first detection of CO emission in "normal" galaxies at z>5 (in the first billion years of cosmic time) together with far-infrared fine structure line tracers of the atomic and ionized gas using the sensitive Atacama Large(sub-)Millimeter Array. We found that early galaxies appear to be extremely gas rich, relative to their stellar content, and to display comparable star formation efficiency to typical lower redshift "normal" galaxies. However, the interstellar medium in a fraction of such galaxies also appears to be strongly affected by lower metallicity, affecting the phase structure of the interstellar medium, and the usefulness of CO as a tracer of molecular gas.
ISBN: 9781392252406Subjects--Topical Terms:
535904
Astrophysics.
Subjects--Index Terms:
Galaxy evolution
An Exploration of Inter-Stellar Gas and Its Role in Galaxy Assembly over Cosmic Time.
LDR
:03592nmm a2200361 4500
001
2272547
005
20201105110120.5
008
220629s2019 ||||||||||||||||| ||eng d
020
$a
9781392252406
035
$a
(MiAaPQ)AAI13883666
035
$a
(MiAaPQ)cornellgrad:11453
035
$a
AAI13883666
040
$a
MiAaPQ
$c
MiAaPQ
100
1
$a
Pavesi, Riccardo.
$3
3549980
245
1 3
$a
An Exploration of Inter-Stellar Gas and Its Role in Galaxy Assembly over Cosmic Time.
260
1
$a
Ann Arbor :
$b
ProQuest Dissertations & Theses,
$c
2019
300
$a
409 p.
500
$a
Source: Dissertations Abstracts International, Volume: 80-12, Section: B.
500
$a
Publisher info.: Dissertation/Thesis.
500
$a
Advisor: Riechers, Dominik.
502
$a
Thesis (Ph.D.)--Cornell University, 2019.
506
$a
This item must not be sold to any third party vendors.
520
$a
The key physical processes driving galaxy formation and evolution are controlled by gas and, in particular, the process of star formation from cold, dense gas is not well understood since it depends upon the gas cooling ability, its dynamical state and complex feedback processes. Galaxies were observed to form stars much more rapidly in the past (~10-11 billion years ago), which may be due to larger gas reservoirs or more efficient star formation processes. While previous studies have identified large molecular gas reservoirs in a few pre-selected star-forming galaxies, an unbiased survey for molecular gas is necessary to provide robust statistical constraints to the gas content of galaxies at the peak epoch of cosmic star formation. Taking advantage of the improved frequency coverage, sensitivity and bandwidth of the upgraded Very Large Array we have carried out the first unbiased survey by performing a deep-field blind search for CO(1-0) line emission at z~2-3 and CO(2-1) line emission at z~5-7, targeting CO(1-0) which is the most commonly used tracer of the cold, dense molecular gas which fuels star formation. Having detected the first CO(1-0)-selected galaxies at high redshift, we have used their luminosity and abundance to provide robust statistical constraints to the CO luminosity function at z~2-3, finding conclusive evidence for a much higher gas mass content relative to galaxies in the local Universe. This finding suggested that evolution in the mechanisms of star formation may not be the dominant contribution to the high observed star formation rates, but rather large amounts of available cold gas. In order to explore how this finding may apply to even higher redshift, we have also achieved the first detection of CO emission in "normal" galaxies at z>5 (in the first billion years of cosmic time) together with far-infrared fine structure line tracers of the atomic and ionized gas using the sensitive Atacama Large(sub-)Millimeter Array. We found that early galaxies appear to be extremely gas rich, relative to their stellar content, and to display comparable star formation efficiency to typical lower redshift "normal" galaxies. However, the interstellar medium in a fraction of such galaxies also appears to be strongly affected by lower metallicity, affecting the phase structure of the interstellar medium, and the usefulness of CO as a tracer of molecular gas.
590
$a
School code: 0058.
650
4
$a
Astrophysics.
$3
535904
653
$a
Galaxy evolution
653
$a
Galaxy formation
653
$a
High redshift universe
653
$a
ISM
690
$a
0596
710
2
$a
Cornell University.
$b
Physics.
$3
3173885
773
0
$t
Dissertations Abstracts International
$g
80-12B.
790
$a
0058
791
$a
Ph.D.
792
$a
2019
793
$a
English
856
4 0
$u
http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=13883666
based on 0 review(s)
Location:
ALL
電子資源
Year:
Volume Number:
Items
1 records • Pages 1 •
1
Inventory Number
Location Name
Item Class
Material type
Call number
Usage Class
Loan Status
No. of reservations
Opac note
Attachments
W9424781
電子資源
11.線上閱覽_V
電子書
EB
一般使用(Normal)
On shelf
0
1 records • Pages 1 •
1
Multimedia
Reviews
Add a review
and share your thoughts with other readers
Export
pickup library
Processing
...
Change password
Login