Evidence of a Fast Evolution of the UV Luminosity
Download
1 / 18

Andrea Grazian INAF - Osservatorio Astronomico di Roma - PowerPoint PPT Presentation


  • 121 Views
  • Uploaded on

Evidence of a Fast Evolution of the UV Luminosity Function of LBGs beyond z=6 from a wide and deep HAWK-I Survey. Andrea Grazian INAF - Osservatorio Astronomico di Roma.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Andrea Grazian INAF - Osservatorio Astronomico di Roma' - nixie


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
Evidence of a Fast Evolution of the UV LuminosityFunction of LBGs beyond z=6 from a wide and deep HAWK-I Survey

Andrea Grazian

INAF - Osservatorio Astronomico di Roma

M. Castellano, A. Fontana, K. Boutsia, R. Bouwens, S. Cristiani, M. Dickinson, F. Fiore, E. Giallongo, M. Giavalisco, A. Koekemoer, R, Maiolino, A. Moorwood, N. Menci, M. Nonino, L. Pentericci, A. Renzini, P. Rosati, S. Salimbeni, P. Santini, E. Vanzella


  • Goals:

  • “exploration” of the Universe: observing galaxies, AGNs and structures up to the earliest phases of the Universe;

  • to reconstruct the history of fundamental physical quantites: Star Formation Rate, Stellar Mass, dust content, morphology, metallicity etc.

  • To Understand the physics involved. Develop and constrain theoretical models.

Pb#1: How can we derive “physical quantities” from a

handful of photons?

Pb#2: We have to select complete galaxy samples by physical properties and not (only) by photometric criteria.


  • Motivation of our ESO HAWK-I Large Program:

  • z=7 is fashionable; availability of HAWK-I.

  • COMPLEMENTARY to deep pencil beam surveys with WFC3

  • Beat the cosmic variance: wide area survey.

  • Possibility to spectroscopically confirm our z=7 relatively bright candidates

ESO LP 181.A.0717 (P.I. A. Fontana)


HAWK-I is a newly-installed wide-field imager at the Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106".

It has 10 observing filters: 4 broad band filters (Y, J, H & K) and 6 narrow band filters (Bracket gamma, CH4, H2, 1.061 μm, 1.187 μm & 2.090 μm).


BDF4 Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106".

GOODS-S

NTTDF

Deep IR Survey with Hawk-I & WFC3

Hawk-I Science Verification

+

ESO LP (HAWK-I+FORS2):

(PI A. Fontana)

WFC3 Early Science Release + Illingworth’s UDF data


ACS - Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106". Z

Hawk-I - Y

Hawk-I is a powerful survey machine, even in WFC3 era.

Yband

WFC3- 1.5hr

Hawk-I 15hr

WFC3 4.7 sq. arcmin

Hawk-I 56.3 sq. arcmin


Hawk-I Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106". Y 15hr

WFC3-J 22hr


Z band Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106".

z=6.8

Y band

z=7

Lyman Break Galaxies at z=7

UV continuum

Lyα


An unexpected , large population of contaminants Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106".

Y

V

B

R

I

Z

To clean the sample: “aggressive”

requirement of non-detection in the UBVRI bands

(ALL <2σ; 4 bands <1σ)


z∼7 candidates in Hawk-I GOODS-S observations Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106".

Castellano et al. 2009

arxiv:0909.2853


Stacking of z∼7 candidates in Hawk-I GOODS-S Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106".

Castellano et al. 2009

arxiv:0909.2853


z∼7 candidates in Hawk-I BDF4 and NTTDF field Nasmyth A focus of the 8 meter UT4 telescope (ESO, Paranal). It is provided with four 2048x2048 pixels detectors for a total field of view of 7.5'x7.5'. The pixel scale is 0.106".

Y

Y


Hawk-I candidates are consistent with WFC3 observations done so far.

I

Z

Y105

J125

UDF

B+V+I

Z

Y

J+H+K

Hawk-I


“Counting” is not enough... need to evaluate systematics so far.

For each set of LF param (α,L*,φ)

Extract expected galaxies in your field (LUV, z)

Repeat N times

Compute Magnitudes (AV, Lyα)

Place them at random position in the image

Perform multicolor extraction

Retain the fraction selected with your favoured criterion

For GOODS-S, about 104 simulations for 106 galaxies..


Clear evidence of a fast evolution of the LF from z=6 to z=7 so far.

Castellano et al. 2009

arxiv:0909.2853

Hawk-I: bright &rare

ERS: intermediate

HUDF: faint & numerous


Candidates @ z ≈ 7 in the WFC3 so far.

Bunker +09 arxiv:0909.2255

Oesch+ 09 arxiv:0909.1806

Yan+ 09 arxiv:0910.0077

McLure+ 09 arxiv 0909.2437


Bouwens+09, arxiv:0909.1803 so far.

The SFRD(z): impact of the uncertainties of WFC3 data.

Yan+09, arxiv:0910.0077


Summary & Conclusions so far.

  • Galaxies at z=7 and 8 are reliably detected with new generation IR imagers - Hawk-I and WFC3 are complementary at Y=25-27 - beyond WFC3 wins.

  • Data interpretation is complex -requires careful evaluation of instrumental and selection effects.

  • 60 hours of FORS2 already awarded for spectroscopy!!

  • Clear evidence for a fast evolution from z=6 to z=7 . beyond is controversial

Castellano et al. 2009 (A&A in press) arXiv:0909.2853


ad