Imaging the water snowline in protostellar envelopes

Content Provider	Scilit
Author	Hoff, Merel L. R. Van ’T
Copyright Year	2017
Description	Determining the locations of the major snowlines in protostellar environments is crucial to fully understand the planet formation process and its outcome. Despite being located far enough from the central star to be spatially resolved with ALMA, the CO snowline remains difficult to detect directly in protoplanetary disks. Instead, its location can be derived from N_{2}$H^{+}$emission, when chemical effects like photodissociation of CO and $N_{2}$are taken into account. The water snowline is even harder to observe than that for CO, because in disks it is located only a few AU from the protostar, and from the ground only the less abundant isotopologue H_{2}$^{18}$O can be observed. Therefore, using an indirect chemical tracer, as done for CO, may be the best way to locate the water snowline. A good candidate tracer is $HCO^{+}$, which is expected to be particularly abundant when its main destructor, $H_{2}$O, is frozen out. Comparison of H_{2}$^{18}$O and $H^{13}CO^{+}$emission toward the envelope of the Class 0 protostar IRAS2A shows that the emission from both molecules is spatially anticorrelated, providing a proof of concept that $H^{13}CO^{+}$can indeed be used to trace the water snowline in systems where it cannot be imaged directly.
Related Links	http://arxiv.org/pdf/1709.09184 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/C90D26878BB8FC95E7A8815F6F1B0765/S1743921317006986a.pdf/div-class-title-imaging-the-water-snowline-in-protostellar-envelopes-div.pdf
Ending Page	94
Page Count	7
Starting Page	88
ISSN	17439213
e-ISSN	17439221
DOI	10.1017/s1743921317006986
Journal	Proceedings of the International Astronomical Union
Issue Number	S332
Volume Number	13
Language	English
Publisher	Cambridge University Press (CUP)
Publisher Date	2017-03-01
Access Restriction	Open
Subject Keyword	Proceedings of the International Astronomical Union Astronomy and Astrophysics Individual (tw Hydrae Protoplanetary Disks
Content Type	Text
Resource Type	Article
Subject	Astronomy and Astrophysics Space and Planetary Science