You are here


Title: The Cow: Discovery Of A Luminous, Hot, And Rapidly Evolving Transient.
Name(s): Prentice, S. J., author
Maguire, K., author
Smartt, S. J., author
Magee, M. R., author
Schady, P., author
Sim, S., author
Chen, T.-W., author
Clark, P., author
Colin, C., author
Fulton, M., author
McBrien, O., author
O'Neill, D., author
Smith, K. W., author
Ashall, C., author
Chambers, K. C., author
Denneau, L., author
Flewelling, H. A., author
Heinze, A., author
Holoien, T. W.-S., author
Huber, M. E., author
Kochanek, C. S., author
Mazzali, P. A., author
Prieto, J. L., author
Rest, A., author
Shappee, B. J., author
Stalder, B., author
Stanek, K. Z., author
Stritzinger, M. D., author
Thompson, T. A., author
Tonry, J. L., author
Type of Resource: text
Genre: Journal Article
Journal Article
Date Issued: 2018-09-20
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: We present the ATLAS discovery and initial analysis of the first 18 days of the unusual transient event, ATLAS18qqn/AT2018cow. It is characterized by a high peak luminosity (similar to 1.7 x 10(44) erg s(-1)),rapidly evolving light curves (>5 mag rise to peak in similar to 3.5 days), and hot blackbody spectra, peaking at similar to 27,000 K that are relatively featureless and unchanging over the first two weeks. The bolometric light curve cannot be powered by radioactive decay under realistic assumptions. The detection of high-energy emission may suggest a central engine as the powering source. Using a magnetar model, we estimated an ejected mass of 0.1-0.4 M-circle dot, which lies between that of low-energy core-collapse events and the kilonova, AT2017gfo. The spectra cooled rapidly from 27,000 to 15,000 K in just over two weeks but remained smooth and featureless. Broad and shallow emission lines appear after about 20 days, and we tentatively identify them as He I although they would be redshifted from their rest wavelengths. We rule out that there are any features in the spectra due to intermediate mass elements up to and including the Fe group. The presence of r-process elements cannot be ruled out. If these lines are due to He, then we suggest a low-mass star with residual He as a potential progenitor. Alternatively, models of magnetars formed in neutron star mergers, or accretion onto a central compact object, give plausible matches to the data.
Identifier: FSU_libsubv1_wos_000444911400001 (IID), 10.3847/2041-8213/aadd90 (DOI)
Keywords: supernovae: general, star, telescope, light curves, explosions, shock breakout, stars: magnetars, magnetars, stars: individual (AT2018cow), stars: neutron, supernova
Publication Note: The publisher’s version of record is available at
Persistent Link to This Record:
Owner Institution: FSU
Is Part Of: Astrophysical Journal Letters.
Issue: iss. 1, vol. 865

Choose the citation style.
Prentice, S. J., Maguire, K., Smartt, S. J., Magee, M. R., Schady, P., Sim, S., … Tonry, J. L. (2018). The Cow: Discovery Of A Luminous, Hot, And Rapidly Evolving Transient. Astrophysical Journal Letters. Retrieved from