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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 Chris Lintott

Professor of Astrophysics and Citizen Science Lead

Research theme

  • Astronomy and astrophysics

Sub department

  • Astrophysics

Research groups

  • Zooniverse
  • Beecroft Institute for Particle Astrophysics and Cosmology
  • Rubin-LSST
chris.lintott@physics.ox.ac.uk
Telephone: 01865 (2)73638
Denys Wilkinson Building, room 532C
www.zooniverse.org
orcid.org/0000-0001-5578-359X
  • About
  • Citizen science
  • Group alumni
  • Publications

Zooniverse labs

Zooniverse lab
Build your own Zooniverse project

The Zooniverse lab lets anyone build their own citizen science project

Zooniverse Lab

Chandra Observations of Galaxy Zoo Mergers: Frequency of Binary Active Nuclei in Massive Mergers

ArXiv 1206.1266 (2012)

Authors:

Stacy H Teng, Kevin Schawinski, C Megan Urry, Dan W Darg, Sugata Kaviraj, Kyuseok Oh, Erin W Bonning, Carolin N Cardamone, William C Keel, Chris J Lintott, Brooke D Simmons, Ezequiel Treister

Abstract:

We present the results from a Chandra pilot study of 12 massive galaxy mergers selected from Galaxy Zoo. The sample includes major mergers down to a host galaxy mass of 10$^{11}$ $M_\odot$ that already have optical AGN signatures in at least one of the progenitors. We find that the coincidences of optically selected active nuclei with mildly obscured ($N_H \lesssim 1.1 \times 10^{22}$ cm$^{-2}$) X-ray nuclei are relatively common (8/12), but the detections are too faint ($< 40$ counts per nucleus; $f_{2-10 keV} \lesssim 1.2 \times 10^{-13}$ erg s$^{-1}$ cm$^{-2}$) to reliably separate starburst and nuclear activity as the origin of the X-ray emission. Only one merger is found to have confirmed binary X-ray nuclei, though the X-ray emission from its southern nucleus could be due solely to star formation. Thus, the occurrences of binary AGN in these mergers are rare (0-8%), unless most merger-induced active nuclei are very heavily obscured or Compton thick.
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Planet Hunters: Assessing the Kepler Inventory of Short Period Planets

ArXiv 1205.6769 (2012)

Authors:

Megan E Schwamb, Chris J Lintott, Debra A Fischer, Matthew J Giguere, Stuart Lynn, Arfon M Smith, John M Brewer, Michael Parrish, Kevin Schawinski, Robert J Simpson

Abstract:

We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of \geq 2 R\oplus planets on short period (< 15 days) orbits based on Planet Hunters detections. We present these results along with an analysis of the detection efficiency of human classifiers to identify planetary transits including a comparison to the Kepler inventory of planet candidates. Although performance drops rapidly for smaller radii, \geq 4 R\oplus Planet Hunters \geq 85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Kepler \geq 4 R\oplus planets suggest suggests the Kepler inventory of \geq 4 R\oplus short period planets is nearly complete.
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Galaxy Zoo and ALFALFA: Atomic Gas and the Regulation of Star Formation in Barred Disc Galaxies

ArXiv 1205.5271 (2012)

Authors:

Karen L Masters, Robert C Nichol, Martha P Haynes, William C Keel, Chris Lintott, Brooke Simmons, Ramin Skibba, Steven Bamford, Riccardo Giovanelli, Kevin Schawinski

Abstract:

We study the observed correlation between atomic gas content and the likelihood of hosting a large scale bar in a sample of 2090 disc galaxies. Such a test has never been done before on this scale. We use data on morphologies from the Galaxy Zoo project and information on the galaxies' HI content from the ALFALFA blind HI survey. Our main result is that the bar fraction is significantly lower among gas rich disc galaxies than gas poor ones. This is not explained by known trends for more massive (stellar) and redder disc galaxies to host more bars and have lower gas fractions: we still see at fixed stellar mass a residual correlation between gas content and bar fraction. We discuss three possible causal explanations: (1) bars in disc galaxies cause atomic gas to be used up more quickly, (2) increasing the atomic gas content in a disc galaxy inhibits bar formation, and (3) bar fraction and gas content are both driven by correlation with environmental effects (e.g. tidal triggering of bars, combined with strangulation removing gas). All three explanations are consistent with the observed correlations. In addition our observations suggest bars may reduce or halt star formation in the outer parts of discs by holding back the infall of external gas beyond bar co-rotation, reddening the global colours of barred disc galaxies. This suggests that secular evolution driven by the exchange of angular momentum between stars in the bar, and gas in the disc, acts as a feedback mechanism to regulate star formation in intermediate mass disc galaxies.
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Probing quasar shutdown timescales with Hanny's Voorwerp

AIP Conference Proceedings 1427 (2012) 193-200

Authors:

DA Evans, K Schawinski, S Virani, CM Urry, WC Keel, P Natarajan, CJ Lintott, A Manning, P Coppi, S Kaviraj, SP Bamford, GIG Józsa, M Garrett, H Van Arkel, P Gay, L Fortson

Abstract:

Galaxy formation is significantly modulated by energy output from supermassive black holes at the centers of galaxies which grow in highly efficient luminous quasar phases. The timescale on which black holes transition into and out of such phases is, however, unknown. We present the first measurement of the shutdown timescale for an individual quasar using Suzaku and XMM-Newton X-ray observations of the nearby galaxy IC 2497, which hosted a luminous quasar no more than ∼230,000 years ago that is still seen as a light echo in 'Hanny's Voorwerp', but whose presentday radiative output is lower by at least 2 and more likely by over 4 orders of magnitude. This extremely rapid shutdown provides new insights into the physics of accretion in supermassive black holes, and may signal a transition of the accretion disk to a radiatively inefficient state. These results were first presented by [1]. © 2012 American Institute of Physics.
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The Milky Way Project: A statistical study of massive star formation associated with infrared bubbles

ArXiv 1203.5486 (2012)

Authors:

Sarah Kendrew, Robert J Simpson, Eli Bressert, Matthew S Povich, Reid Sherman, Chris Lintott, Thomas P Robitaille, Kevin Schawinski, Grace Wolf-Chase

Abstract:

The Milky Way Project citizen science initiative recently increased the number of known infrared bubbles in the inner Galactic plane by an order of magnitude compared to previous studies. We present a detailed statistical analysis of this dataset with the Red MSX Source catalog of massive young stellar sources to investigate the association of these bubbles with massive star formation. We particularly address the question of massive triggered star formation near infrared bubbles. We find a strong positional correlation of massive young stellar objects (MYSOs) and H II regions with Milky Way Project bubbles at separations of < 2 bubble radii. As bubble sizes increase, a statistically significant overdensity of massive young sources emerges in the region of the bubble rims, possibly indicating the occurrence of triggered star formation. Based on numbers of bubble-associated RMS sources we find that 67+/-3% of MYSOs and (ultra)compact H II regions appear associated with a bubble. We estimate that approximately 22+/-2% of massive young stars may have formed as a result of feedback from expanding H II regions. Using MYSO-bubble correlations, we serendipitously recovered the location of the recently discovered massive cluster Mercer 81, suggesting the potential of such analyses for discovery of heavily extincted distant clusters.
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