The evolution of stars and gas in galaxies
This presentation is the property of its rightful owner.
Sponsored Links
1 / 57

The Evolution of Stars and Gas in Galaxies PowerPoint PPT Presentation


  • 75 Views
  • Uploaded on
  • Presentation posted in: General

The Evolution of Stars and Gas in Galaxies. PhD Thesis Proposal Philip Lah. Supervisor: Frank Briggs. Supervisory Panel: Erwin de Blok (RSAA) Jayaram Chengalur (National Centre for Radio Astrophysics, India) Matthew Colless (Anglo-Australian Observatory)

Download Presentation

The Evolution of Stars and Gas in Galaxies

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


The evolution of stars and gas in galaxies

The Evolution of Stars and Gas in Galaxies

PhD Thesis Proposal

Philip Lah


Supervisor frank briggs

Supervisor: Frank Briggs

  • Supervisory Panel:

  • Erwin de Blok (RSAA)

  • Jayaram Chengalur (National Centre for Radio Astrophysics, India)

  • Matthew Colless (Anglo-Australian Observatory)

  • Roberto De Propris (University of Bristol, UK)


Goal of phd

Goal of PhD

  • to relate the evolution in galaxies of their star formation rate, their stellar mass and their mass of neutral hydrogen gas (the fuel of star formation)

  • examine galaxy evolution over last 4 Gyr (going back third age of the universe)

  • study galaxies in a variety of different environments

  • UNIQUE PART study galaxy properties in same systems – optically selected galaxies


Why do this

Why do this?

Should give a clearer picture of how, when and where stars and their host galaxies form.

Improves our understanding of our place in the universe, residing in our galaxy, the Milky Way, and orbiting our star, the Sun.


Background

Background


Star formation rate

 Hα Spectroscopy

 Hα Narrow Band Imaging

 UV (with no dust correction)

Subaru

Field

Star Formation Rate


Stellar mass density

Stellar Mass Density

Dickenson et al. 2003


Neutral hydrogen gas mass

Neutral Hydrogen Gas Mass


Neutral hydrogen gas mass1

Neutral Hydrogen Gas Mass

Storrie-

Lombardi

& Wolfe 2000

Rao & Turnshek 2003

HIPASS

HI 21cm


Galaxy environment

Galaxy Environment

  • galaxy environment cluster, cluster outskirts and the field

  • density - morphology relation

  • density - star formation relation

  • density - neutral hydrogen relation

  • Cause of density relations?


Hi 21cm emission at high redshift

HI 21cm Emission at High Redshift


Previous highest redshift hi

Previous highest redshift HI

Westerbork Synthesis Radio Telescope (WSRT) Netherlands

Abell 2218 z = 0.18

integration time 36 days, Zwaan et al. 2001

Very Large Array (VLA)

Abell 2192 z = 0.1887

integration time ~80 hours, Veheijen et al. 2004


Giant metrewave radio telescope

Giant Metrewave Radio Telescope


Giant metrewave radio telescope1

Giant Metrewave Radio Telescope


Giant metrewave radio telescope2

Giant Metrewave Radio Telescope


Giant metrewave radio telescope3

Giant Metrewave Radio Telescope


Giant metrewave radio telescope4

Giant Metrewave Radio Telescope


Giant metrewave radio telescope5

Giant Metrewave Radio Telescope


Giant metrewave radio telescope6

Giant Metrewave Radio Telescope


Giant metrewave radio telescope7

Giant Metrewave Radio Telescope


Giant metrewave radio telescope8

Giant Metrewave Radio Telescope


Gmrt antenna positions

GMRT Antenna Positions


Gmrt collecting area

GMRT Collecting Area

30 dishes of 45 m diameter

GMRT Collecting Area

 21 × ATCA

 15 × Parkes

 6.9 × WSRT

 3.6 × VLA


Method of hi detection

Method of HI Detection

  • individual galaxies HI 21cm emission below radio observational detection limits

  • large sample of galaxies with known positions & precise redshifts (from optical observations)

  • coadd weak HI signals isolated in position & redshift (velocity) space

  • measure integrated HI signal – total HI mass of whole galaxy population – can calculate the average HI galaxy mass


Observational targets

Observational Targets


Table of targets

Table of Targets


Galaxy cluster abell 370

DEC

Cluster Centre

Galaxy Cluster Abell 370

27’ × 27’

RA


Galaxy cluster abell 3701

DEC

Galaxy Cluster Abell 370

~3’ × 3’

RA


Abell 370 data

Abell 370 Data

  • 42 literature redshifts for Abell 370 cluster members 33 are usable – large error in σz ≥ ± 300 kms-1(from Soucail et al. 1988 )

  • obtaining imaging data ESO 2.2m/WFI with VRI filters 34’ × 33’(queue scheduled by Sept) use to select sample for spectroscopic follow-up

  • using AF2/WYFFOS 4.2mWilliam Herschel Telescope, La Palma (sometime in Oct to Dec)  for redshifts and star formation rate from [OII]


Radio data cube

Frequency

HI Redshift

DEC

RA

Radio Data Cube


Spectrum through cube

galaxy redshift

Spectrum through Cube


Spectrum around redshift

galaxy redshift

Spectrum around Redshift


Flux around galaxy in velocity space

galaxy redshift

Flux around Galaxy in Velocity Space


Hi abell 370

HI Abell 370


Rms decrease

RMS decrease


Mass hi

Mass HI

Assuming an optically thin neutral hydrogen cloud

MHI*= 6.2 ×109 M (Zwaan et al. 2003)


Abell 370 hi mass

Abell 370 HI Mass


Galaxy cluster cl0024 1654

DEC

Cluster Centre

Galaxy Cluster Cl0024+1654

21’ × 21’

RA


Galaxy cluster cl0024 16541

DEC

Galaxy Cluster Cl0024+1654

~1’ × 1’

RA


Cl0024 1654 data

Cl0024+1654 Data

  • HST imaging  2181 galaxies with morphologies of which 195 spectroscopically confirmed cluster members (Treu et al. 2003)

  • Hαnarrow band imaging with Subaru  star formation rates(Kodama et al. 2004)

  • 296 literature redshifts within HI frequency limits of the GMRT observation (Cszoke et al. 2001)

  • estimated HI Mass Upper Limit similar to Abell 370: ~1.7 × 109M


Subaru field

Subaru Field

RA

24’ × 30’

DEC


Subaru field redshifts

GMRT HI Freq Range

Subaru Filter FWHM (120 Å)

Subaru Field Redshifts


Subaru field redshifts1

Subaru Field Redshifts

number of target Hα emitting galaxies = 347

number of galaxies with quality ≥ 3 redshifts = 183

number of galaxies in GMRT HI freq range = 166


Past and future work

Past and Future Work


Previous work

Previous Work

started PhD 1st March 2004

  • Mar to mid-July 1stThree Month Project - preliminary work on reducing Abell 370 GMRT data - creating data reduction pipeline

  • mid-July to Aug completed reduction of one sideband of the 7 days of data - prepared results for a GMRT telescope proposal for galaxy cluster Cl0024+1652

  • Sept to mid-Nov 2ndThree Month Project - 6dFGS working with Robert Proctor and Duncan Forbes (Swinburne University) and Matthew Colless (AAO)


Previous work1

Previous Work

  • mid Nov to Dec Literature Review for Thesis Proposal

  • Jan 2005 traveled to India for GMRT observations galaxy cluster Cl0024+1652

  • beginning of March 5 nights 2dF AAT redshift observations of the Subaru Field

  • have been working on adapting and revising data reduction code for all GMRT data sets – developing partially automated flagging of data


Future work

Future Work

rest 2005:

  • finish data reduction code

  • reduce Subaru data and publish results

  • reduce Cl0024+1652 data and publish results

  • Abell 370 spectroscopic observations  using AF2/WYFFOS 4.2mWilliam Herschel Telescope, La Palma (sometime in Oct to Dec) – for redshifts and star formation rate from [OII]


Future work1

Future Work

2006:

  • beginning year finish reducing Abell 370 data and publish results

  • once published Subaru results may go back to GMRT TAC for another sample of field galaxies

  • other possibilities:

    - obtain more redshifts for coadding particularly on the outskirts of the clusters

    - stellar mass measurements using redshifts and additional near-infrared imaging


Future work2

Future Work

2007:

  • first 6 months - finish write up thesis / finish off anything left over from previous years


The end

The End


Additional slides

Additional Slides


The uv plane

The UV Plane


Abell 370 uv plane

Abell 370 UV plane


Uv plane

UV Plane


Gmrt beam

GMRT Beam


  • Login