# # Program information file # PROGRAM_ID 2022A086 PROGRAM_TITLE An Infrared Perspective on a Stellar Mass-loss Mystery in Symbiotic X-ray Binaries with SpeX and MIRSI PROGRAM_INV1 Ryan Lau PROGRAM_INV2 Kishalay De PROGRAM_INV3 Roberto Soria PROGRAM_INV4 Mansi Kasliwal PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG Symbiotic X-ray Binaries [SyXRBs] host a compact object such as a neutron star [NS] or black hole [BH] that accretes from the winds of a late-type [super]giant companion. The evolved state of the 'donor star' implies that SyXRBs exist in a relatively short-lived phase. SyXRBs therefore present unique laboratories for investigating the formation and evolution of compact objects. Although the first SyXRB was confirmed over 40 years ago, an SyXRB mystery persists on the donor star mass-loss rates: the red [super]giant companions exhibit peculiarly large mass-loss rates as well as high wind velocities. The donor star mass-loss properties have important consequences on the long-term binary evolution as well as the wind-accretion physics of compact objects. SyXRBs are, however, difficult to study at X-ray and optical wavelengths due to their relatively low X-ray luminosities, the intrinsically red nature of the mass donor, and interstellar/circumstellar obscuration. Infrared [IR] observations are therefore well-suited for investigating the mass-loss properties of the mass donors that feed the compact objects in SyXRBs. The key purpose of this proposal is to obtain an independent measurement of the donor star mass-loss rates from star+dust spectral energy distribution [SED] models with IR spectroscopic observations with SpeX between 1 - 5 um and imaging observations with MIRSI at 12 um. We therefore propose for 4.5 hr with IRTF/SpeX [SXD and LXD_Long] and IRTF/MIRSI [N-band] to observe two SyXRBs Scutum X-1 and SRGA J181414.6-225604. Near-simultaneous observations of with SpeX and MIRSI are crucial given the IR variability exhibited by SyXRBs. Since SyXRBs are not commonly studied at IR wavelengths, we aim to demonstrate the feasibility of this technique in order to pursue in the future an IR census of the mass-loss rates for the ~dozen known SyXRBs. PROGRAM_ABSTRACT_END