Studying the onset of deconfinement with multi‐messenger astronomy of neutron stars. Issue 1 (7th February 2021)

• Record Type: Journal Article
• Authors: Blaschke, David; Cierniak, Mateusz
• Other Names: Zen Vasconcellos C.A. guestEditor.; Hess P.O. guestEditor.; Piccinelli G. guestEditor.; Vargas Magaña M. guestEditor.; Ureña-Lopez L. guestEditor.; González Felipe R. guestEditor.; Boller Th. guestEditor.; Gullberg S. guestEditor.
• Is Part Of: Astronomische Nachrichten. Volume 342:Issue 1/2(2021)
• Page Start: 227
• Page End: 233
• Publication Date: 2021-02-07
• Subjects: neutron stars -- quark Deconfinement -- third family compact stars -- maximum mass -- GW170817 -- GW190814 -- PSR J0740 + 6620; Astronomy -- Periodicals; 520.5
• DOI: 10.1002/asna.202113909
• Languages: English
• ISSNs: 0004-6337

Abstract

Abstract: With the first multi‐messenger observation of a binary neutron star merger (GW170817), new constraints became available for masses and radii of neutron stars. We introduce a class of hybrid EoS that fulfills all these constraints and predicts a region in the mass‐radius diagram that could be populated only by hybrid neutron stars with quark matter cores. A confirmation of this conjecture would be provided when the NICER radius measurement for the high‐mass pulsar PSR J0740 + 6620 yields a radius significantly less than 11 km. Would this radius measurement yield a result in excess of 12 km, this would allow for both, a purely hadronic and a hybrid nature of this star. In the latter case, the maximum mass could reach 2.6 M ⊙ so that the lighter object in the asymmetric binary merger GW190814 could have been a hybrid star. We demonstrate that this high mass can be compatible with an early onset of deconfinement for stars with masses below 1 M ⊙ and the occurrence of low‐mass twin stars. In such a case, the remnant of GW170817 could be a long‐lived hypermassive pulsar.