skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Lower limit on the heat capacity of the neutron star core

Authors:
; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1344599
Grant/Contract Number:
FG02-87ER40365; FG02-00ER41132; SC0008808
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 95; Journal Issue: 2; Related Information: CHORUS Timestamp: 2017-02-23 15:13:12; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Cumming, Andrew, Brown, Edward F., Fattoyev, Farrukh J., Horowitz, C. J., Page, Dany, and Reddy, Sanjay. Lower limit on the heat capacity of the neutron star core. United States: N. p., 2017. Web. doi:10.1103/PhysRevC.95.025806.
Cumming, Andrew, Brown, Edward F., Fattoyev, Farrukh J., Horowitz, C. J., Page, Dany, & Reddy, Sanjay. Lower limit on the heat capacity of the neutron star core. United States. doi:10.1103/PhysRevC.95.025806.
Cumming, Andrew, Brown, Edward F., Fattoyev, Farrukh J., Horowitz, C. J., Page, Dany, and Reddy, Sanjay. Tue . "Lower limit on the heat capacity of the neutron star core". United States. doi:10.1103/PhysRevC.95.025806.
@article{osti_1344599,
title = {Lower limit on the heat capacity of the neutron star core},
author = {Cumming, Andrew and Brown, Edward F. and Fattoyev, Farrukh J. and Horowitz, C. J. and Page, Dany and Reddy, Sanjay},
abstractNote = {},
doi = {10.1103/PhysRevC.95.025806},
journal = {Physical Review C},
number = 2,
volume = 95,
place = {United States},
year = {Tue Feb 21 00:00:00 EST 2017},
month = {Tue Feb 21 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevC.95.025806

Citation Metrics:
Cited by: 5works
Citation information provided by
Web of Science

Save / Share:
  • The recent distance determination allowed precise estimation of the orbital parameters of Cyg X-1, which contains a massive 14.8 M{sub Sun} black hole (BH) with a 19.2 M{sub Sun} O star companion. This system appears to be the clearest example of a potential progenitor of a black hole + neutron star (BH-NS) system. We follow the future evolution of Cyg X-1, and show that it will soon encounter a Roche lobe overflow episode, followed shortly by a Type Ib/c supernova and the formation of a neutron star (NS). It is demonstrated that in majority of cases ({approx}> 70%) the supernovamore » and associated natal kick disrupt the binary due to the fact that the orbit expanded significantly in the Roche lobe overflow episode. In the reminder of cases ({approx}< 30%) the newly formed BH-NS system is too wide to coalesce in the Hubble time. Only sporadically ({approx}1%) may a Cyg X-1-like binary form a coalescing BH-NS system given a favorable direction and magnitude of the natal kick. If a Cyg X-1-like channel (comparable mass BH-O star bright X-ray binary) is the only or dominant way to form BH-NS binaries in the Galaxy, then we can estimate the empirical BH-NS merger rate in the Galaxy at the level of {approx}0.001 Myr{sup -1}. This rate is so low that the detection of BH-NS systems in gravitational radiation is highly unlikely, generating Advanced LIGO/VIRGO detection rates at the level of only {approx}1 per century. If BH-NS inspirals are in fact detected, it will indicate that the formation of these systems proceeds via some alternative and yet unobserved channels.« less
  • Wyoming montmorillonite (Volclay) with different charges were produced by Li-incorporation and the interlayer cations were replaced by tetramethyl ammonium. Their XRD pattern showed a regular sequence of expanded and collapsed interlayers. The regularly interstratified structure corresponds to a regularity of Reichweite R = 1. The expanded part of the interlayers was calculated by comparing XRD pattern with simulations using NEWMOD software. The calculations of the cation exchange capacity CEC for the expanded interlayer part gives a constant value of 65 {+-} 2 mmol/100 g fully swellable montmorillonite. This value is denoted as the lower CEC limit of montmorillonite. The authorsmore » propose a model which considers montmorillonite to be a stacked two-dimensional polyelectrolyte. The model proposes that interlayers of the stack collapse spontaneously by cation shifting into the neighboring interlayers, if the charge density of a montmorillonite has a value below the lower CEC value. The shifted cations of the collapsed interlayer increase the charge density in the neighboring interlayers and prevent their collapse. A regularly interstratified structure arises with the sequence expanded/collapsed/expanded interlayer, which can be observed by XRD. The behavior of low charged montmorillonite is explained with the properties of a two-dimensional polyelectrolyte. Below the critical layer charge, the Van der Waals forces dominate over electrostatic repulsive forces and the interlayers collapse.« less
  • The mass of the Galactic dark matter halo is under vivid discussion. A recent study by Xue et al. revised the Galactic halo mass downward by a factor of {approx}2 relative to previous work, based on the line-of-sight velocity distribution of {approx}2400 blue horizontal-branch (BHB) halo stars. The observations were interpreted with a statistical approach using cosmological galaxy formation simulations, as only four of the six-dimensional phase-space coordinates were determined. Here we concentrate on a close investigation of the stars with the highest negative radial velocity from that sample. For one star, SDSSJ153935.67+023909.8 (J1539+0239 for short), we succeed in measuringmore » a significant proper motion, i.e., full phase-space information is obtained. We confirm the star to be a Population II BHB star from an independent quantitative analysis of the Sloan Digital Sky Survey (SDSS) spectrum-providing the first non-LTE (NLTE) study of any halo BHB star-and reconstruct its three-dimensional trajectory in the Galactic potential. J1539+0239 turns out to be the fastest halo star known to date, with a Galactic rest-frame velocity of 694{sup +300}{sub -221} km s{sup -1} (full uncertainty range from Monte Carlo error propagation) at its current position. The extreme kinematics of the star allows a significant lower limit to be put on the halo mass in order to keep it bound, of M {sub halo} {>=} 1.7{sup +2.3}{sub -1.1} x 10{sup 12} M{sub sun}. We conclude that the Xue et al. results tend to underestimate the true halo mass as their most likely mass value is consistent with our analysis only at a level of 4%. However, our result confirms other studies that make use of the full phase-space information.« less
  • The penetration of an orbiting 1 M/sub sun/ neutron star into a 16 M/sub sun/ supergiant companion is investigated. Primary emphasis is placed on the structure and evolution of the massive component. Effects due to turbulent dissipation and frictional drag as well as angular momentum transport are included. It is found that double core evolution leads to either (1) hydrodynamicejection of part of all of the envelope or (2) coalescence of the two cores with little or no mass ejection: possibly resulting in a Thorne-Zytkow object. Some implications regarding the binary pulsar are discussed in the context of the doublemore » core scenario.« less