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.

Prof. Matt Jarvis

Professor of Astrophysics

Research theme

  • Astronomy and astrophysics

Sub department

  • Astrophysics

Research groups

  • Cosmology
  • Galaxy formation and evolution
  • Hintze Centre for Astrophysical Surveys
  • MeerKAT
  • Rubin-LSST
  • The Square Kilometre Array (SKA)
Matt.Jarvis@physics.ox.ac.uk
Telephone: 01865 (2)83654
Denys Wilkinson Building, room 703
  • About
  • Publications

MIGHTEE-H I: the first MeerKAT H I mass function from an untargeted interferometric survey

Monthly Notices of the Royal Astronomical Society Oxford University Press 522:4 (2023) 5308-5319

Authors:

Anastasia A Ponomareva, Matt J Jarvis, Hengxing Pan, Natasha Maddox, Michael G Jones, Bradley S Frank, Sambatriniaina HA Rajohnson, Wanga Mulaudzi, Martin Meyer, Elizabeth AK Adams, Maarten Baes, Kelley M Hess, Sushma Kurapati, Isabella Prandoni, Francesco Sinigaglia, Kristine Spekkens, Madalina Tudorache, Ian Heywood, Jordan D Collier, Srikrishna Sekhar

Abstract:

We present the first measurement of the H I mass function (HIMF) using data from MeerKAT, based on 276 direct detections from the MeerKAT International GigaHertz Tiered Extragalactic Exploration (MIGHTEE) Survey Early Science data covering a period of approximately a billion years (0 ≤ z ≤ 0.084). This is the first HIMF measured using interferometric data over non-group or cluster field, i.e. a deep blank field. We constrain the parameters of the Schechter function that describes the HIMF with two different methods: 1/Vmax and modified maximum likelihood (MML). We find a low-mass slope α=−1.29+0.37−0.26 , ‘knee’ mass log10(M∗/M⊙)=10.07+0.24−0.24 and normalization log10(ϕ∗/Mpc−3)=−2.34+0.32−0.36 (H0 = 67.4 km s−1 Mpc−1) for 1/Vmax , and α=−1.44+0.13−0.10 , ‘knee’ mass log10(M∗/M⊙)=10.22+0.10−0.13 and normalization log10(ϕ∗/Mpc−3)=−2.52+0.19−0.14 for MML. When using 1/Vmax we find both the low-mass slope and ‘knee’ mass to be consistent within 1σ with previous studies based on single-dish surveys. The cosmological mass density of H I is found to be slightly larger than previously reported: ΩHI=5.46+0.94−0.99×10−4h−167.4 from 1/Vmax and ΩHI=6.31+0.31−0.31×10−4h−167.4 from MML but consistent within the uncertainties. We find no evidence for evolution of the HIMF over the last billion years.
More details from the publisher
Details from ORA
More details

The LOFAR Two-metre Sky Survey: Deep Fields data release 1. V. Survey description, source classifications, and host galaxy properties

Monthly Notices of the Royal Astronomical Society Oxford University Press 523:2 (2023) 1729-1755

Authors:

Pn Best, R Kondapally, Wl Williams, Rk Cochrane, Kj Duncan, Cl Hale, P Haskell, K Małek, I McCheyne, Djb Smith, L Wang, A Botteon, M Bonato, M Bondi, G Calistro Rivera, F Gao, G Gürkan, Mj Hardcastle, Matthew J Jarvis, B Mingo, H Miraghaei, Lk Morabito, D Nisbet, I Prandoni, Hja Röttgering, J Sabater, T Shimwell, C Tasse, R van Weeren

Abstract:

Source classifications, stellar masses, and star-formation rates are presented for ≈80 000 radio sources from the first data release of the Low Frequency Array Two-metre Sky Survey (LoTSS) Deep Fields, which represents the widest deep radio survey ever undertaken. Using deep multi-wavelength data spanning from the ultraviolet to the far-infrared, spectral energy distribution (SED) fitting is carried out for all of the LoTSS Deep host galaxies using four different SED codes, two of which include modelling of the contributions from an active galactic nucleus (AGN). Comparing the results of the four codes, galaxies that host a radiative AGN are identified, and an optimized consensus estimate of the stellar mass and star-formation rate for each galaxy is derived. Those galaxies with an excess of radio emission over that expected from star formation are then identified, and the LoTSS Deep sources are divided into four classes: star-forming galaxies, radio-quiet AGN, and radio-loud high-excitation and low-excitation AGN. Ninety-five per cent of the sources can be reliably classified, of which more than two-thirds are star-forming galaxies, ranging from normal galaxies in the nearby Universe to highly-starbursting systems at z > 4. Star-forming galaxies become the dominant population below 150-MHz flux densities of ≈1 mJy, accounting for 90 per cent of sources at S150MHz ∼ 100 μJy. Radio-quiet AGN comprise ≈10 per cent of the overall population. Results are compared against the predictions of the SKADS and T-RECS radio sky simulations, and improvements to the simulations are suggested.
More details from the publisher
Details from ORA
More details

MIGHTEE-H i: possible interactions with the galaxy NGC 895

Monthly Notices of the Royal Astronomical Society Oxford University Press 521:4 (2023) 5177-5190

Authors:

B Namumba, J Román, J Falcón-Barroso, Jh Knapen, R Ianjamasimanana, E Naluminsa, Gig Józsa, M Korsaga, N Maddox, B Frank, S Sikhosana, S Legodi, C Carignan, Aa Ponomareva, T Jarrett, D Lucero, Om Smirnov, Jm Van Der Hulst, Dj Pisano, K Malek, L Marchetti, M Vaccari, M Jarvis, M Baes, M Meyer, Eak Adams, H Chen, J Delhaize, Sha Rajohnson, S Kurapati, I Heywood, L Verdes-Montenegro

Abstract:

The transformation and evolution of a galaxy is strongly influenced by interactions with its environment. Neutral hydrogen (H i) is an excellent way to trace these interactions. Here, we present H i observations of the spiral galaxy NGC 895, which was previously thought to be isolated. High-sensitivity H i observations from the MeerKAT large survey project MIGHTEE reveal possible interaction features, such as extended spiral arms and the two newly discovered H i companions, that drive us to change the narrative that it is an isolated galaxy. We combine these observations with deep optical images from the Hyper Suprime Camera to show an absence of tidal debris between NGC 895 and its companions. We do find an excess of light in the outer parts of the companion galaxy MGTH_J022138.1-052631, which could be an indication of external perturbation and thus possible sign of interactions. Our analysis shows that NGC 895 is an actively star-forming galaxy with a SFR of 1.75 ± 0.09[M⊙/yr], a value typical for high-stellar mass galaxies on the star-forming main sequence. It is reasonable to state that different mechanisms may have contributed to the observed features in NGC 895, and this emphasizes the need to revisit the target with more detailed observations. Our work shows the high potential and synergy of using state-of-the-art data in both H i and optical to reveal a more complete picture of galaxy environments.
More details from the publisher
Details from ORA
More details
More details

The wide-field, multiplexed, spectroscopic facility WEAVE: survey design, overview, and simulated implementation

Monthly Notices of the Royal Astronomical Society Oxford University Press 530:3 (2023) 2688-2730

Authors:

Shoko Jin, Scott Trager, Gavin Dalton, J Alfonso L Aguerri, Janet Drew, Jesús Falcón-Barroso, Boris Gänsicke, Vanessa Hill, Angela Iovino, Matthew Pieri, Bianca Poggianti, Daniel Smith, Antonella Vallenari, Don Carlos Abrams, David Aguado, Yago Ascasibar, Vasily Belokurov, Clotilde Laigle, Alireza Molaeinezhad, David Terrett, James Gilbert, Sarah Hughes, Matt Jarvis, Ian Lewis, Sébastien Peirani, Ellen Schallig, John Stott

Abstract:

WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable ‘mini’ integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366−959 nm at R ∼ 5000, or two shorter ranges at R ∼ 20 000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy’s origins by completing Gaia’s phase-space information, providing metallicities to its limiting magnitude for ∼3 million stars and detailed abundances for ∼1.5 million brighter field and open-cluster stars; (ii) survey ∼0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey ∼400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z < 0.5 cluster galaxies; (vi) survey stellar populations and kinematics in ∼25 000 field galaxies at 0.3 ≲ z ≲ 0.7; (vii) study the cosmic evolution of accretion and star formation using >1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z > 2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.
More details from the publisher
Details from ORA
More details

MIGHTEE: deep 1.4 GHz source counts and the sky temperature contribution of star forming galaxies and active galactic nuclei

Monthly Notices of the Royal Astronomical Society Oxford University Press 520:2 (2022) 2668-2691

Authors:

Cl Hale, Ih Whittam, Mj Jarvis, Pn Best, Nl Thomas, I Heywood, M Prescott, N Adams, J Afonso, Fangxia An, Raa Bowler, Jd Collier, Rhw Cook, R Davé, Bs Frank, M Glowacki, Pw Hatfield, S Kolwa, Cc Lovell, N Maddox, L Marchetti, Lk Morabito, E Murphy, I Prandoni, Z Randriamanakoto, Ar Taylor

Abstract:

We present deep 1.4 GHz source counts from ∼5 deg2 of the continuum Early Science data release of the MeerKAT International Gigahertz Tiered Extragalactic Exploration (MIGHTEE) survey down to S1.4GHz ∼15 μJy. Using observations over two extragalactic fields (COSMOS and XMM-LSS), we provide a comprehensive investigation into correcting the incompleteness of the raw source counts within the survey to understand the true underlying source count population. We use a variety of simulations that account for: errors in source detection and characterisation, clustering, and variations in the assumed source model used to simulate sources within the field and characterise source count incompleteness. We present these deep source count distributions and use them to investigate the contribution of extragalactic sources to the sky background temperature at 1.4 GHz using a relatively large sky area. We then use the wealth of ancillary data covering a subset of the COSMOS field to investigate the specific contributions from both active galactic nuclei (AGN) and star forming galaxies (SFGs) to the source counts and sky background temperature. We find, similar to previous deep studies, that we are unable to reconcile the sky temperature observed by the ARCADE 2 experiment. We show that AGN provide the majority contribution to the sky temperature contribution from radio sources, but the relative contribution of SFGs rises sharply below 1 mJy, reaching an approximate 15-25 per cent contribution to the total sky background temperature (Tb ∼100 mK) at ∼15 μJy.
More details from the publisher
Details from ORA
More details

Pagination

  • First page First
  • Previous page Prev
  • …
  • Page 5
  • Page 6
  • Page 7
  • Page 8
  • Current page 9
  • Page 10
  • Page 11
  • Page 12
  • Page 13
  • …
  • 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