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 Peter Hatfield

Visitor

Research theme

  • Astronomy and astrophysics
  • Lasers and high energy density science

Sub department

  • Astrophysics

Research groups

  • Galaxy formation and evolution
  • Hintze Centre for Astrophysical Surveys
peter.hatfield@physics.ox.ac.uk
peterhatfield.wordpress.com
  • About
  • Publications

MIGHTEE: the nature of the radio-loud AGN population

Monthly Notices of the Royal Astronomical Society Oxford University Press 516:1 (2022) 245-263

Authors:

Ih Whittam, Mj Jarvis, Cl Hale, M Prescott, Lk Morabito, I Heywood, Nj Adams, J Afonso, Fangxia An, Y Ao, Raa Bowler, Jd Collier, Rp Deane, J Delhaize, B Frank, M Glowacki, Pw Hatfield, N Maddox, L Marchetti, Am Matthews, I Prandoni, S Randriamampandry, Z Randriamanakoto, Djb Smith, Ar Taylor, Nl Thomas, M Vaccari

Abstract:

We study the nature of the faint radio source population detected in the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Early Science data in the COSMOS field, focusing on the properties of the radio-loud active galactic nuclei (AGNs). Using the extensive multiwavelength data available in the field, we are able to classify 88 per cent of the 5223 radio sources in the field with host galaxy identifications as AGNs (35 per cent) or star-forming galaxies (54 per cent). We select a sample of radio-loud AGNs with redshifts out to z ∼ 6 and radio luminosities 1020 < L1.4 GHz/W Hz−1 < 1027 and classify them as high-excitation and low-excitation radio galaxies (HERGs and LERGs). The classification catalogue is released with this work. We find no significant difference in the host galaxy properties of the HERGs and LERGs in our sample. In contrast to previous work, we find that the HERGs and LERGs have very similar Eddington-scaled accretion rates; in particular we identify a population of very slowly accreting AGNs that are formally classified as HERGs at these low radio luminosities, where separating into HERGs and LERGs possibly becomes redundant. We investigate how black hole mass affects jet power, and find that a black hole mass ≳ 107.8 M⊙ is required to power a jet with mechanical power greater than the radiative luminosity of the AGN (Lmech/Lbol > 1). We discuss that both a high black hole mass and black hole spin may be necessary to launch and sustain a dominant radio jet.

More details from the publisher
Details from ORA
More details

Quantification of Unknown Unknowns in Astronomy and Physics

ArXiv 2207.13993 (2022)
Details from ArXiV

MIGHTEE: the nature of the radio-loud AGN population

ArXiv 2207.12379 (2022)

Authors:

IH Whittam, MJ Jarvis, CL Hale, M Prescott, LK Morabito, I Heywood, NJ Adams, J Afonso, Fangxia An, Y Ao, RA Bowler, JD Collier, RP Deane, J Delhaize, B Frank, M Glowacki, PW Hatfield, N Maddox, L Marchetti, AM Matthews, I Prandoni, S Randriamampandry, Z Randriamanakoto, DJB Smith, AR Taylor, NL Thomas, M Vaccari
Details from ArXiV

Hybrid photometric redshifts for sources in the COSMOS and XMM-LSS fields

(2022)

Authors:

PW Hatfield, MJ Jarvis, N Adams, RAA Bowler, B Häußler, KJ Duncan
More details from the publisher
Details from ArXiV

Looking at the distant universe with the MeerKAT array: discovery of a luminous OH megamaser at z > 0.5

Astrophysical Journal Letters IOP Science 931:1 (2022) L7

Authors:

Marcin Glowacki, Jordan D Collier, Amir Kazemi-Moridani, Bradley Frank, Hayley Roberts, Jeremy Darling, Hans-Rainer Kloeckner, Nathan Adams, Andrew J Baker, Matthew Bershady, Tariq Blecher, Sarah-Louise Blyth, Rebecca Bowler, Barbara Catinella, Laurent Chemin, Steven M Crawford, Catherine Cress, Romeel Dave, Roger Deane, Erwin de Blok, Jacinta Delhaize, Kenneth Duncan, Ed Elson, Sean February, Eric Gawiser, Peter Hatfield, Julia Healy, Patricia Henning, Kelley M Hess, Ian Heywood, Benne W Holwerda, Munira Hoosain, John P Hughes, Zackary L Hutchens, Matt Jarvis, Sheila Kannappan, Neal Katz, Dusan Keres, Marie Korsaga, Renee C Kraan-Korteweg, Philip Lah, Michelle Lochner, Natasha Maddox, Sphesihle Makhathini, Gerhardt R Meurer, Martin Meyer, Danail Obreschkow, Se-Heon Oh, Tom Oosterloo

Abstract:

In the local universe, OH megamasers (OHMs) are detected almost exclusively in infrared-luminous galaxies, with a prevalence that increases with IR luminosity, suggesting that they trace gas-rich galaxy mergers. Given the proximity of the rest frequencies of OH and the hyperfine transition of neutral atomic hydrogen (H i), radio surveys to probe the cosmic evolution of H i in galaxies also offer exciting prospects for exploiting OHMs to probe the cosmic history of gas-rich mergers. Using observations for the Looking At the Distant Universe with the MeerKAT Array (LADUMA) deep H i survey, we report the first untargeted detection of an OHM at z > 0.5, LADUMA J033046.20-275518.1 (nicknamed "Nkalakatha"). The host system, WISEA J033046.26-275518.3, is an infrared-luminous radio galaxy whose optical redshift z ≈ 0.52 confirms the MeerKAT emission-line detection as OH at a redshift z OH = 0.5225 ± 0.0001 rather than H i at lower redshift. The detected spectral line has 18.4σ peak significance, a width of 459 ± 59 km s-1, and an integrated luminosity of (6.31 ± 0.18 [statistical] ± 0.31 [systematic]) × 103 L ⊙, placing it among the most luminous OHMs known. The galaxy's far-infrared luminosity L FIR = (1.576 ±0.013) × 1012 L ⊙ marks it as an ultraluminous infrared galaxy; its ratio of OH and infrared luminosities is similar to those for lower-redshift OHMs. A comparison between optical and OH redshifts offers a slight indication of an OH outflow. This detection represents the first step toward a systematic exploitation of OHMs as a tracer of galaxy growth at high redshifts.
More details from the publisher
Details from ORA
More details

Pagination

  • First page First
  • Previous page Prev
  • Page 1
  • Page 2
  • Page 3
  • Current page 4
  • Page 5
  • Page 6
  • Page 7
  • Page 8
  • Page 9
  • …
  • 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