A Glimpse into the Cosmos: SO2 and SO Abundances

In the frigid realms surrounding an intermediate mass protostar, scientists have detected high quantities of sulfur dioxide (SO2) and sulfur monoxide (SO). This exciting discovery hints that these molecules could be forming on icy dust grains before escaping into the gas phase through a captivating process known as photodesorption.

Introducing Innovative Techniques to Measure Photodesorption

In groundbreaking research, we present findings on the photodesorption yields for SO2 and tentatively for SO when subjected to ultraviolet (UV) light. Ice samples of SO2 were exposed to varying temperatures between 14 and 80 Kelvin, and the results were measured meticulously using a calibrated quadrupole mass spectrometer.

Impressive Yields and Temperature Effects on SO2 Photodesorption

At a chilling 14 K, the yields for photodesorption were recorded at an impressive 2.3 x 10⁻⁴ molecules per photon for SO2 and 6 x 10⁻⁵ molecules per photon for SO. Notably, the yield of SO2 increased with rising temperatures, peaking at 3.8 x 10⁻⁴ molecules per photon at 70 K, before declining at 80 K. This decrease may be attributed to crystallization processes within the sample.

The Constant Mystery of SO: A Stable Signal in Flux

Interestingly, the photodesorption signal for SO remained relatively stable across varying temperatures, demonstrating intriguing behavior that warrants further investigation. These calculated yields have been integrated into the Nautilus gas-grain chemical model, providing valuable insights into the contributions of SO2 and SO to gas-phase abundances in astronomical environments.

Exciting Insights into SO3 and Interstellar IR Spectra

Additionally, we provide a theoretical estimation for the band strength of the 1395 cm⁻¹ SO3 infrared feature, calculated at 1.1 x 10⁻¹⁶ cm molecules⁻¹. SO3 emerges as a significant product in irradiated SO2 ices and may play a vital role in the 7.2 μm band observed in certain interstellar ice infrared spectra.

Meet the Brilliant Minds Behind the Research

This exhilarating study was brought to life by the talented team of Rafael Martín-Doménech, Bruno Escribano, David Navarro-Almaida, Angèle Taillard, Héctor Carrascosa, Guillermo M. Muñoz Caro, and Asunción Fuente, each contributing to our understanding of these cosmic processes.