29 citations · 61 across the 8 of their papers we have counts for
8 papers
Five years of 6.7 GHz methanol maser monitoring with Irbene radio telescopes
A. Aberfelds, J. Šteinbergs, I. Shmeld +1
We present the results of a 5-year monitoring program of 42 sources targeted at 6.7 GHz methanol masers, conducted from March 2017 to October 2022 using the Irbene 32 and 16 meter…
Milliarcsecond structure and variability of methanol maser emission in three high-mass protostars
A Aberfelds, A Bartkiewicz, M Szymczak +5
{The variability study of 6.7\,GHz methanol masers has become a useful way to improve our understanding of the physical conditions in high-mass star-forming regions.} {Based on the…
New ex-OH maser detections in the northern celestial hemisphere
O. Patoka, O. Antyufeyev, I. Shmeld +5
Aims.Molecular masers, including methanol and hydroxyl masers, and in particular the ones in excited rotational states (ex-OHmasers), are one of the most informative tools for stud…
The Effects of Subsurface Chemistry in the Grain Mantles on the Deuterium Chemistry in Molecular Clouds
Juris Kalvans, Ivar Shmeld
The deuterium enrichment in molecules in dark molecular cloud cores and starforming regions is usually attributed to gas-phase chemistry. Here we examine the effects of surface and…
Chemical fractionation of deuterium in the protosolar nebula
J. Kalvans, I. Shmeld, J. R. Kalnin +1
Understanding gas-grain chemistry of deuterium in star-forming objects may help to explain their history and present state. We aim to clarify how processes in ices affect the deute…
Modeling the processing of interstellar ices by energetic particles
Juris Kalvāns, Ivar Shmeld
Context. Interstellar ice is the main form of metal species in dark molecular clouds. Experiments and observations have shown that the ice is significantly processed after the free…
The Effect of an Inert Solid Reservoir on Molecular Abundances in Dense Interstellar Clouds
Juris Kalvans, Ivar Shmeld
The question, what is the role of freeze-out of chemical species in determining the molecular abundances in the interstellar gas is a matter of debate. We investigate a theoretical…
Subsurface chemistry of mantles of interstellar dust grains in dark molecular cores
Juris Kalvans, Ivar Shmeld
Context. The abundances of many observed compounds in interstellar molecular clouds still lack an explanation, despite extensive research that includes both gas and solid (dust-gra…