ALMA对PSR B1259-63/LS 2883在非活跃期的观测：可变的星周盘？
ALMA Observations of PSR B1259-63/LS 2883 in an Inactive Period: Variable Circumstellar Disk?
摘要：
我们报告了阿塔卡马大型毫米/亚毫米阵列（ALMA）对伽马射线双星系统的观测，该系统包含脉冲星PSR B1259-63，该脉冲星在2017年和2021年近星点通道之间的非活跃期围绕大质量恒星LS 2883运行。我们在97 GHz（频段3）和343 GHz（频段7）检测到无线电连续辐射的二进制系统。与我们之前在2017年近星点通过后不久进行的ALMA观测相比，通量在97 GHz和343 GHz处分别减少了6倍和2倍。343 GHz的通量相对于97 GHz的通量较大，似乎是来自LS 2883周围的星周盘的热辐射。343 GHz通量的减少可能表明盘已经膨胀并变得部分光学薄，因为盘不再受脉冲星风的影响。97 GHz的通量与脉冲星脉冲发射的预期一致，这表明通过脉冲星-盘或脉冲星-恒星风相互作用产生的非脉冲发射已经消失。该系统的图像与点源一致，没有显示出喷出物的迹象。
英文摘要：
We report Atacama Large Millimeter/submillimeter Array (ALMA) observations of the gamma-ray binary system containing the pulsar PSR B1259-63 orbiting around a massive star LS 2883 in an inactive period between the 2017 and 2021 periastron passages. We detected radio continuum emission from the binary system at 97 GHz (Band 3) and 343 GHz (Band 7). Compared with our previous ALMA observations performed soon after the 2017 periastron passage, the fluxes have decreased by an factor of six at 97 GHz and two at 343 GHz. The flux at 343 GHz is large relative to that at 97 GHz and appears to be thermal emission from the circumstellar disk around LS 2883. The decrease of the 343 GHz flux may indicate that the disk has expanded and become partially optically-thin since the disk is no longer affected by pulsar winds. The flux at 97 GHz is consistent with that expected from the pulsed emission from the pulsar, which indicates that the unpulsed emission that had been produced through pulsar-disk or pulsar-stellar wind interaction has disappeared. The image of the system is consistent with a point source and shows no sign of ejecta.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
