arXiv subjects

T. S. Molyarova

Publications and source records attributed to T. S. Molyarova.

2 recordsLinked to original sources

arXiv2026

Optical Spectroscopy of the IR Source CPM 19 and Surrounding Objects

Optical spectra of the well-known infrared source CPM~19, which exhibited a strong decline in brightness during the period from 1984--1987 to 2000--2005, have been obtained for the first time. A strong and broad H$α$ emission line has been detected, along with the possible presence of [S II] emission. No traces of an absorption spectrum are observed. It is suggested that the optical component of CPM 19 is in the pre-main-sequence stage. Various explanations of the observed properties are considered; a plausible scenario is that CPM 19 may belong to the class of UX Ori-type stars with an unusually long eclipse duration, similar to that observed in V1184 Tau. Spectra of other nebulous objects in the vicinity of CPM 19, including the HH objects HH 940 and HH 941, have also been obtained and discussed.

astro-ph.SR↗

arXiv2025

The impact of rates of reactions with cosmic ray induced photons on chemical composition of protoplanetary discs

Cosmic rays and cosmic ray induced photons are vital components of chemical evolution in areas of interstellar medium that are impenetrable by external ultraviolet radiation. However, rates of reactions with cosmic ray induced photons used in astrochemical models were calculated for molecular clouds and can be different in protoplanetary discs, where dust grows up to larger sizes. Using ANDES astrochemical model, we study how an increase in both upper dust size and rates of reactions with cosmic ray induced photons can influence species abundances in protoplanetary discs. We show that the increase in these reactions' rates has a significant impact on the ice mass fraction in area between 2 and 20 au but has little impact on ionisation degree in disc.

astro-ph.EP↗