Woo Jin Kwon

Abstract We present the first results from the B-fields In STar-forming Region Observations (BISTRO) survey, using the Sub-millimetre Common-User Bolometer Array 2 camera, with its associated polarimeter (POL-2), on the James Clerk Maxwell Telescope in Hawaii. We discuss the survey’s aims and objectives. We describe the rationale behind the survey, and the questions that the survey will aim to answer. The most important of these is the role of magnetic fields in the star formation process on the

Abstract We present 850 μ m imaging polarimetry data of the ρ Oph-A core taken with the Submillimeter Common-User Bolometer Array-2 (SCUBA-2) and its polarimeter (POL-2) as part of our ongoing survey project, -fields In STar forming RegiOns (BISTRO). The polarization vectors are used to identify the orientation of the magnetic field projected on the plane of the sky at a resolution of 0.01 pc. We identify 10 subregions with distinct polarization fractions and angles in the 0.2 pc ρ Oph-A core; s

We present continuum observations at 1.3 and 2.7 mm using the Combined Array for Research in Millimeter-wave Astronomy (CARMA) toward six protoplanetary disks in the Taurus molecular cloud: CI Tau, DL Tau, DO Tau, FT Tau, Haro 6-13, and HL Tau. We constrain physical properties of the disks with Bayesian inference using two disk models; flared power-law disk model and flared accretion disk model. Comparing the physical properties, we find that the more extended disks are less flared and that the

We performed spectral line observations of CO J=2-1, 13CO J=1-0, and C18O J=1-0 and polarimetric observations in the 1.3 mm continuum and CO J=2-1 toward a multiple protostar system, L1448 IRS 3, in the Perseus molecular complex at a distance of ~250 pc, using the BIMA array. In the 1.3 mm continuum, two sources (IRS 3A and 3B) were clearly detected with estimated envelope masses of 0.21 and 1.15 solar masses, and one source (IRS 3C) was marginally detected with an upper mass limit of 0.03 solar

Abstract We present 850 μ m polarimetric observations toward the Serpens Main molecular cloud obtained using the POL-2 polarimeter on the James Clerk Maxwell Telescope as part of the B-fields In STar-forming Region Observations survey. These observations probe the magnetic field morphology of the Serpens Main molecular cloud on about 6000 au scales, which consists of cores and six filaments with different physical properties such as density and star formation activity. Using the histogram of rel

Abstract The first step toward planet formation is grain growth from (sub)micrometer to millimeter/centimeter sizes. Grain growth has been reported not only in Class II protoplanetary disks but also in Class 0/I protostellar envelopes. However, early-stage grain growth occurring in Class 0/I stages has rarely been observed on the protostellar disk scale. Here we present the results from the Atacama Large Millimeter/submillimeter Array Band 3 ( λ = 3.1 mm) and 7 ( λ = 0.87 mm) archival data of th

Abstract Interstellar complex organic molecules (COMs) in solar-like young stellar objects (YSOs), particularly within protostellar disks, are of significant interest owing to their potential connection to prebiotic chemistry in emerging planetary systems. We report the discovery of a rotating feature enriched in COMs, including CH 3 OH, CH 3 CHO, and NH 2 CHO, in the protostellar core G192.12-11.10. By constructing a YSO model, we find that the COM-rich feature is likely located within or near

We describe an experimental method to calibrate an absorption imaging system for ultracold atom clouds. Optical density profiles of an atom cloud are obtained for various probe beam intensities and are analyzed to determine the correction factor for the effective probe beam intensity directly from saturation effects. We find that the temporal shape of the probe-beam pulse needs to be taken into account for a quantitative analysis of the optical density measured in saturation absorption imaging.

Abstract Magnetic fields play a significant role in star-forming processes on core to clump scales. We investigate magnetic field orientations and strengths in the massive star-forming clump P2 within the filamentary infrared dark cloud G28.34+0.06 using dust polarization observations made using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the B-field In STar-forming Region Observations (or BISTRO) survey. We compare the magnetic field orientations at the clump scale of ∼

In the past few decades a big picture of low mass star formation has successfully been drawn. However, high mass star formation is little known yet, mainly due to its complexity, distance, and rarity. The Photodetector Array Camera and Spectrometer (PACS) on-board the Herschel Space Observatory (Herschel) has newly provided imaging spectroscopy with unprecedented angular resolution and sensitivity at far-infrared wavelengths. We present Herschel PACS data toward 10 high mass young stellar object

Physical properties of the three main structures in young stellar objects (YSOs), envelopes,
\nbipolar outflows, and circumstellar disks, have been studied using radio interferometers: the
\nBerkeley-Illinois-Maryland Association (BIMA) array and the Combined Array for Research
\nin Millimeter-wave Astronomy (CARMA).
\n(1) Envelopes: Three Class 0 YSOs (L1448 IRS 2, L1448 IRS 3, and L1157) have
\nbeen observed by CARMA at 1.3 mm and 2.7 mm continuum. Through visibility modeli