Surveys of clumps, cores, and condensations in Cygnus-X: SMA observations of SiO (5$-$4)

Abstract

The SiO emissions are usually used to trace high-velocity outflow shocks in star-forming regions. However, several studies have found low-velocity and widespread SiO emissions not associated with outflows in molecular clouds. We aim to detect and characterize the SiO emissions in massive dense cores (MDCs), and explore the properties of the central sources of SiO emission. We present high-angular-resolution ($\sim$1.5${}^{\prime \prime }$) observations of the SiO (5$-$4) line made with the Submillimeter Array towards a sample of 48 MDCs in the Cygnus-X star-forming complex. We studied the SiO emission structures, including their morphologies, kinematics, and energetics, and investigated their relationship with the evolution of the central sources. The SiO (5$-$4) emission is detected in 16 out of 48 MDCs. We identify 14 bipolar and 18 unipolar SiO (5$-$4) outflows associated with 29 dust condensations. Most outflows (24 out of 32) are associated with excess Spitzer 4.5 $\mu$m emissions. We also find diffuse low-velocity ($\Delta v$ $\le$ 1.2 km s${}^{-1}$) SiO (5$-$4) emission closely surrounding the dust condensations in two MDCs, and suggest that it may originate from decelerated outflow shocks or large-scale shocks from global cloud collapse. We find that the SMA SiO (5$-$4) emission in MDCs is mostly associated with outflows. Probably due to the relatively high excitation of SiO (5$-$4) compared to SiO (2$-$1) and due to the spatial filtering effect, we do not detect large-scale low-velocity SiO (5$-$4) emission, but detect more compact low-velocity emission in close proximity to the dust condensations. We group the sources into different evolutionary stages based on the infrared emission, radio continuum emission, and gas temperature properties of the outflow central sources, and find that the 24 $\mu$m luminosity tends to increase with evolution.

47 pages, 24 figures,4 tables, accepted for publication in A&A

References in corpus (19)

• Cold Dark Clouds: The Initial Conditions for Star Formation
• The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X
• A Class I and Class II Methanol Maser Survey of Extended Green Objects (EGOs) from the GLIMPSE Survey
• SiO line emission from C-type shock waves : interstellar jets and outflows
• Fragmentation of Molecular Clumps and Formation of Protocluster
• Warm SiO gas in molecular bullets associated with protostellar outflows
• Spitzer IRAC and MIPS Imaging of Clusters and Outflows in 9 High-mass Star Forming Regions
• Outflows from Massive YSOs as Seen with the Infrared Array Camera
• SiO emission from low- and high-velocity shocks in Cygnus-X massive dense clumps
• The Formation of Stellar Clusters in Magnetized, Filamentary Infrared Dark Clouds
• Tracing extended low-velocity shocks through SiO emission - Case study of the W43-MM1 ridge
• High Resolution Imaging of Molecular Outflows in Massive Young Stars
• Surveys of Clumps, Cores, and Condensations in Cygnus X: I. a New Catalog of ~0.1 pc Massive Dense Cores
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Ubiquitous Protostellar Outflows
• A train of shocks at 3000 au scale? Exploring the clash of an expanding bubble into the NGC 1333 IRAS 4 region. SOLIS XIV
• The DR21(OH) Trident -- Resolving the Massive Ridge into Three Entangled Fibers As the Initial Condition of Cluster Formation
• ORion Alma New GEneration Survey (ORANGES) I. Dust continuum and free-free emission of OMC-2/3 filament protostars
• Connecting Galactic and extragalactic outflows: From the Cygnus-X cluster to active galaxies
• Surveys of Clumps, Cores, and Condensations in the Cygnus X: II. Radio Properties of the Massive Dense Cores

Cited by in corpus (3)

• The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). XII. Unanchored Forked Stream in the Propagating Path of a Protostellar Outflow
• ALMA observations of massive clouds in the central molecular zone: slim filaments tracing parsec-scale shocks
• Surveys of clumps, cores, and condensations in Cygnus-X: Searching for Keplerian disks on the scale of 500 au