Skip to main content
Home
Department Of Physics text logo
  • Research
    • Our research
    • Our research groups
    • Our research in action
    • Research funding support
    • Summer internships for undergraduates
  • Study
    • Undergraduates
    • Postgraduates
  • Engage
    • For alumni
    • For business
    • For schools
    • For the public
Menu
Black Hole

Lensing of space time around a black hole. At Oxford we study black holes observationally and theoretically on all size and time scales - it is some of our core work.

Credit: ALAIN RIAZUELO, IAP/UPMC/CNRS. CLICK HERE TO VIEW MORE IMAGES.

Andrew Bunker

Professor of Astrophysics

Research theme

  • Astronomy and astrophysics

Sub department

  • Astrophysics

Research groups

  • Galaxy formation and evolution
Andy.Bunker@physics.ox.ac.uk
Telephone: 01865 (2)83126
Denys Wilkinson Building, room 702
  • About
  • Publications

Predicting future space near-ir grism surveys using the WFC3 infrared spectroscopic parallels survey

Astrophysical Journal 779:1 (2013)

Authors:

JW Colbert, H Teplitz, H Atek, A Bunker, M Rafelski, N Ross, C Scarlata, AG Bedregal, A Dominguez, A Dressler, A Henry, M Malkan, CL Martin, D Masters, P McCarthy, B Siana

Abstract:

We present near-infrared emission line counts and luminosity functions from the Hubble Space Telescope Wide Field Camera 3 Infrared Spectroscopic Parallels (WISP) program for 29 fields (0.037 deg2) observed using both the G102 and G141 grism. Altogether we identify 1048 emission line galaxies with observed equivalent widths greater than 40 Å, 467 of which have multiple detected emission lines. We use simulations to correct for significant (>20%) incompleteness introduced in part by the non-dithered, non-rotated nature of the grism parallels. The WISP survey is sensitive to fainter flux levels ((3-5) × 10-17 erg s-1 cm-2) than the future space near-infrared grism missions aimed at baryonic acoustic oscillation cosmology ((1-4) × 10-16 erg s-1 cm-2), allowing us to probe the fainter emission line galaxies that the shallower future surveys may miss. Cumulative number counts of 0.7 < z < 1.5 galaxies reach 10,000 deg-2 above an Hα flux of 2 × 10-16 erg s-1 cm-2. Hα-emitting galaxies with comparable [O III] flux are roughly five times less common than galaxies with just Hα emission at those flux levels. Galaxies with low Hα/[O III] ratios are very rare at the brighter fluxes that future near-infrared grism surveys will probe; our survey finds no galaxies with Hα/[O III] < 0.95 that have Hα flux greater than 3 × 10-16 erg s -1 cm-2. Our Hα luminosity function contains a comparable number density of faint line emitters to that found by the Near IR Camera and Multi-Object Spectrometer near-infrared grism surveys, but significantly fewer (factors of 3-4 less) high-luminosity emitters. We also find that our high-redshift (z = 0.9-1.5) counts are in agreement with the high-redshift (z = 1.47) narrowband Hα survey of HiZELS (Sobral et al.), while our lower redshift luminosity function (z = 0.3-0.9) falls slightly below their z = 0.84 result. The evolution in both the Hα luminosity function from z = 0.3-1.5 and the [O III] luminosity function from z = 0.7-2.3 is almost entirely in the L parameter, which steadily increases with redshift over those ranges. © 2013. The American Astronomical Society. All rights reserved..
More details from the publisher
More details

Spectroscopy of z ~ 7 candidate galaxies: Using Lyman-alpha to constrain the neutral fraction of hydrogen in the high-redshift universe

(2013)

Authors:

Joseph Caruana, Andrew J Bunker, Stephen M Wilkins, Elizabeth R Stanway, Silvio Lorenzoni, Matt J Jarvis, Holly Elbert
More details from the publisher

Low masses and high redshifts: The evolution of the mass-metallicity relation

Astrophysical Journal Letters 776:2 (2013)

Authors:

A Henry, C Scarlata, A Domínguez, M Malkan, CL Martin, B Siana, H Atek, AG Bedregal, JW Colbert, M Rafelski, N Ross, H Teplitz, AJ Bunker, A Dressler, N Hathi, D Masters, P McCarthy, A Straughn

Abstract:

We present the first robust measurement of the high redshift mass-metallicity (MZ) relation at 108 ≲ M/M ⊙ ≲ 1010, obtained by stacking spectra of 83 emission-line galaxies with secure redshifts between 1.3 ≲ z ≲ 2.3. For these redshifts, infrared grism spectroscopy with the Hubble Space Telescope Wide Field Camera 3 is sensitive to the R 23 metallicity diagnostic: ([O II] λλ3726, 3729 + [O III] λλ4959, 5007)/Hβ. Using spectra stacked in four mass quartiles, we find a MZ relation that declines significantly with decreasing mass, extending from 12+log(O/H) = 8.8 at M = 109.8 M ⊙, to 12+log(O/H) = 8.2 at M = 10 8.2 M ⊙. After correcting for systematic offsets between metallicity indicators, we compare our MZ relation to measurements from the stacked spectra of galaxies with M ≳ 109.5 M ⊙ and z ∼ 2.3. Within the statistical uncertainties, our MZ relation agrees with the z ∼ 2.3 result, particularly since our somewhat higher metallicities (by around 0.1 dex) are qualitatively consistent with the lower mean redshift (z = 1.76) of our sample. For the masses probed by our data, the MZ relation shows a steep slope which is suggestive of feedback from energy-driven winds, and a cosmological downsizing evolution where high mass galaxies reach the local MZ relation at earlier times. In addition, we show that our sample falls on an extrapolation of the star-forming main sequence (the SFR-M * relation) at this redshift. This result indicates that grism emission-line selected samples do not have preferentially high star formation rates (SFRs). Finally, we report no evidence for evolution of the mass-metallicity-SFR plane; our stack-averaged measurements show excellent agreement with the local relation. © 2013. The American Astronomical Society. All rights reserved.
More details from the publisher
More details

Low Masses and High Redshifts: The Evolution of the Mass-Metallicity Relation

(2013)

Authors:

Alaina Henry, Claudia Scarlata, Alberto Dominguez, Matthew Malkan, Crystal L Martin, Brian Siana, Hakim Atek, Alejandro G Bedregal, James W Colbert, Marc Rafelski, Nathaniel Ross, Harry Teplitz, Andrew J Bunker, Alan Dressler, Nimish Hathi, Daniel Masters, Patrick McCarthy, Amber Straughn
More details from the publisher

Theoretical predictions for the effect of nebular emission on the broad band photometry of high-redshift galaxies

(2013)

Authors:

Stephen M Wilkins, William Coulton, Joseph Caruana, Rupert Croft, Tiziana Di Matteo, Nishikanta Khandai, Yu Feng, Andrew Bunker, Holly Elbert
More details from the publisher

Pagination

  • First page First
  • Previous page Prev
  • …
  • Page 63
  • Page 64
  • Page 65
  • Page 66
  • Current page 67
  • Page 68
  • Page 69
  • Page 70
  • Page 71
  • …
  • Next page Next
  • Last page Last

Footer Menu

  • Contact us
  • Giving to the Dept of Physics
  • Work with us
  • Media

User account menu

  • Log in

Follow us

FIND US

Clarendon Laboratory,

Parks Road,

Oxford,

OX1 3PU

CONTACT US

Tel: +44(0)1865272200

University of Oxfrod logo Department Of Physics text logo
IOP Juno Champion logo Athena Swan Silver Award logo

© University of Oxford - Department of Physics

Cookies | Privacy policy | Accessibility statement

Built by: Versantus

  • Home
  • Research
  • Study
  • Engage
  • Our people
  • News & Comment
  • Events
  • Our facilities & services
  • About us
  • Current students
  • Staff intranet