TY - JOUR
T1 - Velocity-coherent Filaments in NGC 1333
T2 - Evidence for Accretion Flow?
AU - Chen, Michael Chun Yuan
AU - Francesco, James Di
AU - Rosolowsky, Erik
AU - Keown, Jared
AU - Pineda, Jaime E.
AU - Friesen, Rachel K.
AU - Caselli, Paola
AU - Chen, How Huan
AU - Matzner, Christopher D.
AU - Offner, Stella S.
AU - Punanova, Anna
AU - Redaelli, Elena
AU - Scibelli, Samantha
AU - Shirley, Yancy
N1 - Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved.
PY - 2020/3/1
Y1 - 2020/3/1
N2 - Recent observations of global velocity gradients across and along molecular filaments have been interpreted as signs of gas accreting onto and along these filaments, potentially feeding star-forming cores and protoclusters. The behavior of velocity gradients in filaments, however, has not been studied in detail, particularly on small scales (<0.1 pc). In this paper, we present MUFASA, an efficient, robust, and automatic method to fit ammonia lines with multiple velocity components, generalizable to other molecular species. We also present CRISPy, a Python package to identify filament spines in 3D images (e.g., position-position-velocity cubes), along with a complementary technique to sort fitted velocity components into velocity-coherent filaments. In NGC 1333, we find a wealth of velocity gradient structures on a beam-resolved scale of ∼0.05 pc. Interestingly, these local velocity gradients are not randomly oriented with respect to filament spines and their perpendicular, i.e., radial, component decreases in magnitude toward the spine for many filaments. Together with remarkably constant velocity gradients on larger scales along many filaments, these results suggest a scenario in which gas falling onto filaments is progressively damped and redirected to flow along these filaments.
AB - Recent observations of global velocity gradients across and along molecular filaments have been interpreted as signs of gas accreting onto and along these filaments, potentially feeding star-forming cores and protoclusters. The behavior of velocity gradients in filaments, however, has not been studied in detail, particularly on small scales (<0.1 pc). In this paper, we present MUFASA, an efficient, robust, and automatic method to fit ammonia lines with multiple velocity components, generalizable to other molecular species. We also present CRISPy, a Python package to identify filament spines in 3D images (e.g., position-position-velocity cubes), along with a complementary technique to sort fitted velocity components into velocity-coherent filaments. In NGC 1333, we find a wealth of velocity gradient structures on a beam-resolved scale of ∼0.05 pc. Interestingly, these local velocity gradients are not randomly oriented with respect to filament spines and their perpendicular, i.e., radial, component decreases in magnitude toward the spine for many filaments. Together with remarkably constant velocity gradients on larger scales along many filaments, these results suggest a scenario in which gas falling onto filaments is progressively damped and redirected to flow along these filaments.
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U2 - 10.3847/1538-4357/ab7378
DO - 10.3847/1538-4357/ab7378
M3 - Article
AN - SCOPUS:85083919890
SN - 0004-637X
VL - 891
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 84
ER -