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.

Dr Aprajita Verma

Senior Research Fellow

Research theme

  • Astronomy and astrophysics

Sub department

  • Astrophysics

Research groups

  • Zooniverse
  • Astronomical instrumentation
  • Galaxy formation and evolution
  • Rubin-LSST
  • Extremely Large Telescope
aprajita.verma@physics.ox.ac.uk
Telephone: 01865 (2)73374
Denys Wilkinson Building, room 760
  • About
  • Outreach
  • Teaching
  • Publications

Interstellar medium conditions in z similar to 0.2 Lyman-break analogs

ASTRONOMY & ASTROPHYSICS 606 (2017) ARTN A86

Authors:

A Contursi, AJ Baker, S Berta, B Magnelli, D Lutz, J Fischer, A Verma, M Nielbock, JG Carpio, S Veilleux, E Sturm, R Davies, R Genzel, S Hailey-Dunsheath, R Herrera-Camus, A Janssen, A Poglitsch, A Sternberg, LJ Tacconi
More details from the publisher
Details from ORA
More details

Large Synoptic Survey Telescope Galaxies Science Roadmap

(2017)

Authors:

Brant E Robertson, Manda Banerji, Michael C Cooper, Roger Davies, Simon P Driver, Annette MN Ferguson, Henry C Ferguson, Eric Gawiser, Sugata Kaviraj, Johan H Knapen, Chris Lintott, Jennifer Lotz, Jeffrey A Newman, Dara J Norman, Nelson Padilla, Samuel J Schmidt, Graham P Smith, J Anthony Tyson, Aprajita Verma, Idit Zehavi, Lee Armus, Camille Avestruz, L Felipe Barrientos, Rebecca AA Bowler, Malcom N Bremer, Christopher J Conselice, Jonathan Davies, Ricardo Demarco, Mark E Dickinson, Gaspar Galaz, Andrea Grazian, Benne W Holwerda, Matt J Jarvis, Vishal Kasliwal, Ivan Lacerna, Jon Loveday, Phil Marshall, Emiliano Merlin, Nicola R Napolitano, Thomas H Puzia, Aaron Robotham, Samir Salim, Mauro Sereno, Gregory F Snyder, John P Stott, Patricia B Tissera, Norbert Werner, Peter Yoachim, Kirk D Borne, Members of the LSST Galaxies Science Collaboration
More details from the publisher

Large sSynoptic Survey Telescope Galaxies Science Roadmap

(2017)

Authors:

BE Robertson, M Banerji, MC Cooper, Roger Davies, SP Driver, Ferguson, HC Ferguson, E Gawiser, S Kaviraj, JH Knapen, Chris Lintott, J Lotz, JA Newman, DJ Norman, N Padilla, SJ Schmidt, GP Smith, JA Tyson, Aprajita Verma, I Zehavi, L Armus, C Avestruz, LF Barrientos, Rebecca AA Bowler, MN Bremer, CJ Conselice, J Davies, R Demarco, ME Dickinson, G Galaz, A Grazian, BW Holwerda, Matthew Jarvis, V Kasliwal, I Lacerna, J Loveday, P Marshall, E Merlin, NR Napolitano, TH Puzia, A Robotham, S Salim, M Sereno, GF Snyder, JP Stott, PB Tissera, N Werner, P Yoachim, KD Borne

Abstract:

The Large Synoptic Survey Telescope (LSST) will enable revolutionary studies of galaxies, dark matter, and black holes over cosmic time. The LSST Galaxies Science Collaboration has identified a host of preparatory research tasks required to leverage fully the LSST dataset for extragalactic science beyond the study of dark energy. This Galaxies Science Roadmap provides a brief introduction to critical extragalactic science to be conducted ahead of LSST operations, and a detailed list of preparatory science tasks including the motivation, activities, and deliverables associated with each. The Galaxies Science Roadmap will serve as a guiding document for researchers interested in conducting extragalactic science in anticipation of the forthcoming LSST era.
More details from the publisher
Details from ORA
Details from ArXiV

The interstellar medium in high-redshift submillimeter galaxies as probed by infrared spectroscopy

Astrophysical Journal IOP Publishing 837:12 (2017)

Authors:

JL Wardlow, A Cooray, W Osage, N Bourne, D Clements, H Dannerbauer, L Dunne, S Dye, S Eales, D Farrah, C Furlanetto, E Ibar, R Ivison, S Maddox, MM Michałowski, D Riechers, Dimitra Rigopoulou, D Scott, MWL Smith, L Wang, PVD Werf, E Valiante, I Valtchanov, Aprajita Verma

Abstract:

Submillimeter galaxies (SMGs) at $z\gtrsim1$ are luminous in the far-infrared and have star-formation rates, SFR, of hundreds to thousands of solar masses per year. However, it is unclear whether they are true analogs of local ULIRGs or whether the mode of their star formation is more similar to that in local disk galaxies. We target these questions by using Herschel-PACS to examine the conditions in the interstellar medium (ISM) in far-infrared luminous SMGs at z~1-4. We present 70-160 micron photometry and spectroscopy of the [OIV]26 micron, [FeII]26 micron, [SIII]33 micron, [SiII]34 micron, [OIII]52 micron, [NIII]57 micron, and [OI]63 micron fine-structure lines and the S(0) and S(1) hydrogen rotational lines in 13 lensed SMGs identified by their brightness in early Herschel data. Most of the 13 targets are not individually spectroscopically detected and we instead focus on stacking these spectra with observations of an additional 32 SMGs from the \herschel\ archive -- representing a complete compilation of PACS spectroscopy of SMGs. We detect [OI]63 micron, [SiII]34 micron, and [NIII]57 micron at >3sigma in the stacked spectra, determining that the average strengths of these lines relative to the far-IR continuum are $(0.36\pm0.12)\times10^{-3}$, $(0.84\pm0.17)\times10^{-3}$, and $(0.27\pm0.10)\times10^{-3}$, respectively. Using the [OIII]52/[NIII]57 emission line ratio we show that SMGs have average gas-phase metallicities $\gtrsim Z_{\rm sun}$. By using PDR modelling and combining the new spectral measurements with integrated far-infrared fluxes and existing [CII]158 micron data we show that SMGs have average gas densities, n, of $\sim10^{1-3}{\rm cm^{-3}}$ and FUV field strengths, $G_0\sim10^{2.2-4.5}$ (in Habing units: $1.6\times10^{-3}{\rm erg~cm^{-2}~s^{-1}}$), consistent with both local ULIRGs and lower luminosity star-forming galaxies.
More details from the publisher
Details from ORA
More details
Details from ArXiV

Evidence that the AGN dominates the radio emission in z ~ 1 radio-quiet quasars

Monthly Notices of the Royal Astronomical Society Oxford University Press 468:1 (2017) 217-238

Authors:

SV White, Matthew Jarvis, E Kalfountzou, MJ Hardcastle, A Verma, JM Cao Orjales, J Stevens

Abstract:

In order to understand the role of radio-quiet quasars (RQQs) in galaxy evolution, we must determine the relative levels of accretion and star-formation activity within these objects. Previous work at low radio flux densities has shown that accretion makes a significant contribution to the total radio emission, in contrast with other quasar studies that suggest star formation dominates. To investigate, we use 70 RQQs from the Spitzer-Herschel Active Galaxy Survey. These quasars are all at z ∼ 1, thereby minimizing evolutionary effects, and have been selected to span a factor of ∼100 in optical luminosity, so that the luminosity dependence of their properties can be studied. We have imaged the sample using the Karl G. Jansky Very Large Array (JVLA), whose high sensitivity results in 35 RQQs being detected above 2σ. This radio data set is combined with far-infrared luminosities derived from grey-body fitting to Herschel photometry. By exploiting the far-infrared-radio correlation observed for star-forming galaxies, and comparing two independent estimates of the star-formation rate, we show that star formation alone is not sufficient to explain the total radio emission. Considering RQQs above a 2σ detection level in both the radio and the far-infrared, 92 per cent are accretion dominated, and the accretion process accounts for 80 per cent of the radio luminosity when summed across the objects. The radio emission connected with accretion appears to be correlated with the optical luminosity of the RQQ, whilst a weaker luminosity dependence is evident for the radio emission connected with star formation.

More details from the publisher
Details from ORA
More details
More details
Details from ArXiV

Pagination

  • First page First
  • Previous page Prev
  • …
  • Page 8
  • Page 9
  • Page 10
  • Page 11
  • Current page 12
  • Page 13
  • Page 14
  • Page 15
  • Page 16
  • …
  • 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