A Deep Search for Complex Organic Molecules toward the Protoplanetary Disk of V883 Ori

Abstract

Complex organic molecules (COMs) in the form of prebiotic molecules are potential building blocks of life. Using Atacama Large Millimeter/submillimeter Array Band 7 observations in spectral scanning mode, we carried out a deep search for COMs within the disk of V883 Ori, covering a frequency range of ∼348–366 GHz. V883 Ori is an FU Orionis object currently undergoing an accretion burst, which increases its luminosity and consequently increases the temperature of the surrounding protoplanetary disk, facilitating the detection of COMs in the gas phase. We identify 26 molecules, including 14 COMs and 12 other molecules, with first detection in this source of the molecules CH _3 OD, H _2 C ^17 O, and ${{\rm{H}}}_{2}^{13}{\rm{CO}}$ . We searched for multiple nitrogen-bearing COMs, as ${{\rm{CH}}}_{3}{\rm{CN}}$ was the only N-bearing COM that had been identified so far in this source. We also detect ${{\rm{CH}}}_{3}{\rm{CN}}$ , and tentatively detect CH _3 CH _2 CN, ${{\rm{CH}}}_{{\rm{2}}}{\rm{CHCN}}$ , CH _3 NCO, and NH _2 CHO. We compare the abundances relative to methanol (CH _3 OH) with those in the handful of objects with previous detections of these species: the Class 0 protostars IRAS 16293-2422 A, IRAS 16293-2422 B, and B1-c; the high-mass star-forming region Sagittarius B2 (North) (Sgr B2(N)); the solar system comet 67P/Churyumov-Gerasimenko (67P/C-G); and the protoplanetary disk of Oph-IRS 48. We report ∼1–3 orders of magnitude higher abundances compared to Class 0 protostars and ∼1–3 orders of magnitude lower abundances compared to the protoplanetary disk, Sgr B2(N), and 67P/C-G. These results indicate that the protoplanetary disk phase could contribute to the buildup of COMs.

Keywords

• Complex organic molecules
• Pre-biotic astrochemistry
• FU Orionis stars
• Protoplanetary disks