{"id":630,"date":"2026-11-10T14:49:15","date_gmt":"2026-11-10T13:49:15","guid":{"rendered":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/?p=630"},"modified":"2026-11-10T14:56:21","modified_gmt":"2026-11-10T13:56:21","slug":"gamma-ray-modes-in-a-transitional-pulsar","status":"publish","type":"post","link":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/gamma-ray-modes-in-a-transitional-pulsar\/","title":{"rendered":"Gamma-Ray Modes in a Transitional Pulsar"},"content":{"rendered":"<div class=\"wpb-content-wrapper\" id=\"wpb-content-root\"><p>[vc_row][vc_column width=&#8221;2\/3&#8243;][vc_column_text]Transitional millisecond pulsars (tMSPs) are an elite group of compact binary millisecond pulsars that alternate between a radio pulsar state and an accretion disk state. They exhibit a unique subluminous disk state, characterized by rapid switches between two modes and occasional flares. During the mode switching, the radio emission is anticorrelated with the X-ray emission.<\/p>\n<p>The average gamma-ray emission in the disk state is a factor of ~10 brighter than in the pulsar state. However, its origin is still not clear, and the sensitivity of the Fermi-LAT gamma-ray telescope is not sufficient to detect individual modes directly.<br \/>\nIn this work, we study the GeV emission of the prototypical tMSP PSR J1023+0038.<\/p>\n<p>Using available X-ray observations performed with NICER, XMM-Newton, Swift\/XRT, and NuSTAR, we identify all high- and low-mode intervals and analyze the Fermi-LAT data corresponding to each mode.<br \/>\nWe significantly detect the source in both modes and surprisingly we discover that gamma rays and X-rays are anticorrelated during this mode switching: the gamma-ray flux is higher in the X-ray low mode, and vice versa.<br \/>\nThis contradicts the current leading model, which predicts bright gamma-ray emission only in the X-ray high mode.<br \/>\nWe suggest that in the gamma-ray high-mode the jet emission may be dominant in the GeV band.<br \/>\nWe also discuss an alternative interpretation where the gamma-ray emission is powered by 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We present the discovery of gamma-ray modes in PSR J1023+0038, the first confirmed tMSP, from stacking Fermi-LAT data during the modes (which we identify using simultaneous X-ray observations).<\/p>\n","protected":false},"author":3,"featured_media":632,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24,8,18],"tags":[],"class_list":["post-630","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-article","category-news","category-blog-outreach","category-24","category-8","category-18","description-off"],"_links":{"self":[{"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/posts\/630","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/comments?post=630"}],"version-history":[{"count":1,"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/posts\/630\/revisions"}],"predecessor-version":[{"id":631,"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/posts\/630\/revisions\/631"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/media\/632"}],"wp:attachment":[{"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/media?parent=630"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/categories?post=630"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/home.phys.ntnu.no\/LOVE-NEST\/wp-json\/wp\/v2\/tags?post=630"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}