ALMA Reveals Thermal and Nonthermal Desorption of Methanol Ice in the HD 100546 Protoplanetary Disk

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A90106%2F25%3A00646353" target="_blank" >RIV/67985815:90106/25:00646353 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.3847/1538-4357/adb287" target="_blank" >https://doi.org/10.3847/1538-4357/adb287</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/adb287" target="_blank" >10.3847/1538-4357/adb287</a>

Result language

angličtina

Original language name

ALMA Reveals Thermal and Nonthermal Desorption of Methanol Ice in the HD 100546 Protoplanetary Disk

Original language description

Methanol (CH3OH) and formaldehyde (H2CO) are chemically coupled organic molecules proposed to act as an intermediate step between simple molecules and more complex prebiotic compounds. Their abundance distributions across disks regulate the prebiotic potential of material at different disk radii. We present observations of multiple methanol and formaldehyde transitions toward the Herbig Ae disk HD 100546 obtained with the Atacama Large Millimeter/submillimeter Array, building upon the previous serendipitous detection of methanol in this source. We find that methanol has a higher rotational temperature (Trot) than formaldehyde toward both the centrally concentrated emission component in the inner disk (0-110 au) and a radially separate dust ring farther out in the disk (180-260 au). Trot decreases for methanol and formaldehyde from the inner ( 152-27+35 K and 76-8+9 K) to the outer disk ( 52-6+8 K and 31-2+2 K), suggesting that we are tracing two different chemical environments. Trot for both species in the inner disk is consistent with thermal desorption as the origin, while the outer disk reservoir is driven by nonthermal desorption. The CH3OH/H2CO column density ratio decreases from 14.6-4.6+5.2 in the inner disk to 1.3-0.2+0.3 in the outer disk, consistent with modeling predictions. The CH3OH/H2CO column density ratio for the inner disk is consistent with the median value in the range of column density ratios compiled from solar system comets, which would have formed at a similar distance. This supports the notion that interstellar ice is inherited and preserved by protoplanetary disks around solar-mass and intermediate-mass stars as we are seeing fresh ice sublimation, as well as providing more evidence for the presence of prebiotic precursor molecules in planet-forming regions.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

—

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Volume of the periodical

982

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

26

Pages from-to

62

UT code for WoS article

001448662300001

EID of the result in the Scopus database

2-s2.0-105000764749