Supernova and Tc
PRL 106, 081101 (2011)
Selected for a Viewpoint in Physics PHYSICAL REVIEW LETTERS
week ending 25 FEBRUARY 2011
Rapid Cooling of the Neutron Star in Cassiopeia A Triggered by Neutron Superfluidity in Dense Matter
Dany Page,1 Madappa Prakash,2 James M. Lattimer,3 and Andrew W. Steiner4
´ ´ ´ Instituto de Astronomıa, Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510, Mexico 2 Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701-2979, USA 3 Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, New York 11794-3800, USA 4 Joint Institute for Nuclear Astrophysics, National Superconducting Cyclotron Laboratory and, Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA (Received 29 November 2010; published 22 February 2011) We propose that the observed cooling of the neutron star in Cassiopeia A is due to enhanced neutrino emission from the recent onset of the breaking and formation of neutron Cooper pairs in the 3 P2 channel. We find that the critical temperature for this superfluid transition is ’ 0:5 Â 109 K. The observed rapidity of the cooling implies that protons were already in a superconducting state with a larger critical temperature. This is the first direct evidence that superfluidity and superconductivity occur at supranuclear densities within neutron stars. Our prediction that this cooling will continue for several decades at the present rate can be tested by continuous monitoring of this neutron star.
DOI: 10.1103/PhysRevLett.106.081101 PACS numbers: 97.60.Jd, 95.30.Cq, 26.60.Àc
1
The neutron star in Cassiopeia A (Cas A), discovered in 1999 in the Chandra first light observation [1] targeting the supernova remnant, is the youngest known in the Milky Way. An association with the historical supernova SN 1680 [2] gives Cas A an age of 330 yr, in agreement with its kinematic age [3]. The distance to the remnant is estimated to be 3:4þ0:3 kpc [4]. The
Selected for a Viewpoint in Physics PHYSICAL REVIEW LETTERS
week ending 25 FEBRUARY 2011
Rapid Cooling of the Neutron Star in Cassiopeia A Triggered by Neutron Superfluidity in Dense Matter
Dany Page,1 Madappa Prakash,2 James M. Lattimer,3 and Andrew W. Steiner4
´ ´ ´ Instituto de Astronomıa, Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510, Mexico 2 Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701-2979, USA 3 Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, New York 11794-3800, USA 4 Joint Institute for Nuclear Astrophysics, National Superconducting Cyclotron Laboratory and, Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA (Received 29 November 2010; published 22 February 2011) We propose that the observed cooling of the neutron star in Cassiopeia A is due to enhanced neutrino emission from the recent onset of the breaking and formation of neutron Cooper pairs in the 3 P2 channel. We find that the critical temperature for this superfluid transition is ’ 0:5 Â 109 K. The observed rapidity of the cooling implies that protons were already in a superconducting state with a larger critical temperature. This is the first direct evidence that superfluidity and superconductivity occur at supranuclear densities within neutron stars. Our prediction that this cooling will continue for several decades at the present rate can be tested by continuous monitoring of this neutron star.
DOI: 10.1103/PhysRevLett.106.081101 PACS numbers: 97.60.Jd, 95.30.Cq, 26.60.Àc
1
The neutron star in Cassiopeia A (Cas A), discovered in 1999 in the Chandra first light observation [1] targeting the supernova remnant, is the youngest known in the Milky Way. An association with the historical supernova SN 1680 [2] gives Cas A an age of 330 yr, in agreement with its kinematic age [3]. The distance to the remnant is estimated to be 3:4þ0:3 kpc [4]. The