A5043471337- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Vehicle emissions and performance
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Scientific Research and Discoveries
- Atmospheric Ozone and Climate
- Molecular Spectroscopy and Structure
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Spectroscopy and Laser Applications
- Diverse Approaches in Healthcare and Education Studies
- X-ray Diffraction in Crystallography
- Astrophysical Phenomena and Observations
- SAS software applications and methods
- Astronomical Observations and Instrumentation
- Ionosphere and magnetosphere dynamics
- Particle Accelerators and Free-Electron Lasers
- Physics of Superconductivity and Magnetism
- Adaptive optics and wavefront sensing
- Phase Equilibria and Thermodynamics
- Marine and Coastal Research
- Space Exploration and Technology
- Geophysics and Gravity Measurements
Institut für Palliative Care
2023-2024
California Institute of Technology
2015-2024
Infrared Processing and Analysis Center
2015-2024
Ames Research Center
2018-2022
Universities Space Research Association
2022
University of Florida
2013-2018
Korea Astronomy and Space Science Institute
2012
We study the core mass function (CMF) of massive protocluster G286.21+0.17 with Atacama Large Millimeter/submillimeter Array via 1.3~mm continuum emission at a resolution 1.0\arcsec\ (2500~au). have mapped field 5.3\arcmin$\times$5.3\arcmin\ centered on clump. measure CMF in central region, exploring various detection algorithms, which give source numbers ranging from 60 to 125, depending parameter selection. estimate completeness corrections due imperfect flux recovery and identification...
Context: Core accretion models of massive star formation require the existence massive, starless cores within molecular clouds. Yet, only a small number candidates for such truly monolithic are currently known. Aims: Here we analyse core in well-studied infrared-dark cloud (IRDC) called 'dragon cloud' (also known as G028.37+00.07 or 'Cloud C'). This (C2c1) sits at end chain roughly equally spaced actively star-forming near centre IRDC. Methods: We present new high-angular resolution 1 mm...
We report the highest spatial resolution measurement of magnetic fields in M17 using thermal dust polarization taken by SOFIA/HAWC+ centered at 154 $\mu$m wavelength. Using Davis-Chandrasekhar-Fermi method, we found presence strong $980 \pm 230\;\mu$G and $1665 885\;\mu$G lower-density (M17-N) higher-density (M17-S) regions, respectively. The field morphology M17-N possibly mimics gravitational collapse molecular cores while M17-S run perpendicular to matter structure display a pillar an...
We study the probability distribution function (PDF) of mass surface densities, $\Sigma$, infrared dark cloud (IRDC) G028.37+00.07 and its surrounding giant molecular cloud. This PDF constrains physical processes, such as turbulence, magnetic fields self-gravity, that are expected to be controlling structure star formation activity. The chosen IRDC is particular interest since it has almost 100,000 solar masses within a radius 8 parsecs, making one most massive, dense structures known thus...
Aims. Infrared dark clouds represent the earliest stages of high-mass star formation. Detailed observations their physical conditions on all scales are required to improve our understanding role in fueling
We present our second set of results from mid-infrared imaging survey Milky Way Giant HII regions. used the FORCAST instrument on Stratospheric Observatory For Infrared Astronomy to obtain 20 and 37$\mu$m images central ~10'X10' area M17. investigate small- large-scale properties M17 using data in conjunction with previous multi-wavelength observations. The spectral energy distributions individual compact sources were constructed Spitzer-IRAC, SOFIA-FORCAST, Herschel-PACS photometry fitted...
We present SOFIA-upGREAT observations of [CII] emission Infrared Dark Cloud (IRDC) G035.39-00.33, designed to trace its atomic gas envelope and thus test models the origins such clouds. Several velocity components are detected, tracing structures that at a wide range distances in Galactic plane. find main component is likely associated with IRDC immediate surroundings. This strongest has similar $^{13}$CO(2-1) IRDC, but offset by $\sim3\:{\rm km\:s}^{-1}$ larger width $\sim9\:{\rm...
Abstract We discuss the first results from our mid-infrared (MIR) imaging survey of Milky Way Giant H ii (GH ) regions with detailed analysis W51A, which is one largest GH in Galaxy. used FORCAST instrument on Stratospheric Observatory For Infrared Astronomy (SOFIA) to obtain 20 and 37 μ m images central 10′ × 20′ area, encompasses both G49.5–0.4 G49.4–0.3 subregions. Based these new data, conjunction previous multiwavelength observations, we conjecture physical nature several individual...
Abstract We conduct a census of the high-mass protostellar population ∼70,000 M ⊙ infrared dark cloud (IRDC) G028.37+00.07, identifying 35 sources based on their 70 μ m emission, as reported in Herschel Hi-GAL catalog Molinari et al. perform aperture photometry to construct spectral energy distributions, which are then fit with massive protostar models Zhang & Tan. find that span range isotropic luminosities from ∼20 4500 L . The most luminous predicted have current masses * ∼ 10 forming...
Context. Infrared dark clouds (IRDCs) are cold, dense regions of the interstellar medium (ISM) that likely to represent initial conditions for massive star and cluster formation. It is thus important study physical chemical IRDCs provide constraints inputs theoretical models these processes. Aims. We aim determine astrochemical conditions, especially cosmic ray ionisation rate (CRIR) age, in different IRDC G28.37+00.07 by comparing observed abundances multiple molecules molecular ions with...
Abstract Magnetic fields may play a crucial role in setting the initial conditions of massive star and cluster formation. To investigate this, we report SOFIA-HAWC+ 214 μ m observations polarized thermal dust emission high-resolution GBT-Argus C 18 O(1-0) toward Infrared Dark Cloud (IRDC) G28.37+0.07. Considering local dispersion B -field orientations, produce map strength IRDC, which exhibits values between ∼0.03 1 mG based on refined Davis–Chandrasekhar–Fermi method proposed by Skalidis...
Abstract We introduce new analysis methods for studying the star cluster formation processes in Orion A, especially examining scenario of a cloud–cloud collision. utilize CARMA–NRO survey 13CO (1–0) data to compare molecular gas properties young stellar objects from SDSS III IN-SYNC survey. show that increase $v_{\rm {}^{13}CO} - v_{\rm YSO}$ and Σ scatter older YSOs can be signals SOFIA-upGREAT 158 μm [C ii] archival toward northern part A are also compared test whether position velocity...
Progress in understanding star formation requires detailed observational constraints on the initial conditions, i.e. dense clumps and cores giant molecular clouds that are verge of gravitational instability. Such structures have been studied by their extinction Near-Infrared (NIR) and, more recently, Mid-Infrared (MIR) background light. It has somewhat a surprise to find there regions appear as dark shadows at Far-Infrared (FIR) wavelengths long $\sim$100$\mu m$. Here we develop analysis...
We conducted simultaneous 22 GHz water maser and 44 class I methanol surveys of newly identified 282 H2 emission features from the 2.122 μm narrowband image survey in Galactic plane (UWISH2 project) using Korean VLBI Network 21 m radio telescopes. detected 16 13 new sources, respectively. This result indicates that at least ∼5% originate young stellar objects (YSOs) are right physical condition to produce masers. The masers closely related current outflow activities plane. power sources...
Abstract We study the gas kinematics and dynamics of massive protocluster G286.21+0.17 with Atacama Large Millimeter/submillimeter Array using spectral lines C 18 O(2–1), <?CDATA ${{\rm{N}}}_{2}{{\rm{D}}}^{+}$?> (3–2), ${\mathrm{DCO}}^{+}$?> $\mathrm{DCN}$?> (3–2). On parsec clump scale, O emission appears highly filamentary around systemic velocity, are more closely associated dust continuum, is strongly concentrated toward center, where no or only weak detection seen for , possibly due to...
We present spectroscopic tests of MIR to FIR extinction laws in IRDC G028.36+00.07, a potential site massive star and cluster formation. Lim & Tan (2014) developed methods mapping this source using ${\it Spitzer}$-MIPS ${\rm 24\mu m}$ Herschel}$-PACS 70\mu images, by comparing Spitzer}$-IRAC $3$--${\rm 8\mu maps, found tentative evidence for grain growth the highest mass surface density regions. Here we results infrared (SIREX) Spitzer}$-IRS (14 38\mu m}$) data same IRDC. These allow us...
White paper describes efforts to improve our understanding of the life cycle dust. Paper highlights need for multi-wavelength spectroscopy and continuum observations study main sources dust production how grain compositions sizes change locally across cosmic time.
Abstract This is the fourth paper exploring infrared properties of giant H ii regions with FORCAST instrument on Stratospheric Observatory For Infrared Astronomy (SOFIA). Our survey utilizes census 56 Milky Way identified by Conti & Crowther, and in this we present 20 37 μ m imaging data obtained from SOFIA for sources Sgr D W42. Based upon other multiwavelength data, derive discuss detailed physical individual compact subregions as well large-scale However, improved measurements have...
We present the detections of shocked molecular hydrogen (H2) gas in near- and mid-infrared broad CO millimeter from mixed-morphology supernova remnant (SNR) HB~3 (G132.7+1.3) using Palomar WIRC, Spitzer GLIMPSE360 WISE surveys, HHSMT. Our near-infrared narrow-band filter H2 2.12 micron images show that both IRAC 4.6 emission originates gas. The morphology exhibits thin filamentary structures a large scale interaction sites between nearby clouds. Half HB~3, southern eastern shell SNR, emits...
Magnetic fields may play a crucial role in setting the initial conditions of massive star and cluster formation. To investigate this, we report SOFIA-HAWC+ $214\:\mu$m observations polarized thermal dust emission high-resolution GBT-Argus C$^{18}$O(1-0) toward Infrared Dark Cloud (IRDC) G28.37+0.07. Considering local dispersion $B$-field orientations, produce map strength IRDC, which exhibits values between $\sim0.03 - 1\:$mG based on refined Davis-Chandrasekhar-Fermi (r-DCF) method proposed...
Abstract We present our sixth set of results from mid-infrared imaging survey Milky Way Giant H ii regions with detailed analysis NGC 3603, the most luminous giant (GH ) region in Galaxy. used data FORCAST instrument on Stratospheric Observatory For Infrared Astronomy (SOFIA) at 20 and 37 μ m, which mapped central ∼8.′5 × 8.′5 infrared-emitting area 3603 a spatial resolution ≲3″. Utilizing these SOFIA conjunction multiwavelength observations near-infrared to radio, including Spitzer-IRAC...
Abstract We present our third set of results from mid-infrared imaging survey Milky Way Giant H ii regions with detailed analysis W49A, one the most distant, yet luminous, GH in Galaxy. used FORCAST instrument on Stratospheric Observatory For Infrared Astronomy (SOFIA) to obtain 20 and 37 μ m images entire ∼5.′0 × 3.′5 infrared-emitting area W49A at a spatial resolution ∼3″. Utilizing these SOFIA data conjunction previous multiwavelength observations near-infrared radio, including...
We present our sixth set of results from mid-infrared imaging survey Milky Way Giant HII regions with detailed analysis NGC 3603, the most luminous GHII region in Galaxy. used data FORCAST instrument on Stratospheric Observatory For Infrared Astronomy (SOFIA) at 20 and 37 microns which mapped central ~8.5'x8.5' infrared-emitting area 3603 a spatial resolution <~3". Utilizing these SOFIA conjunction multi-wavelength observations near-infrared to radio, including Spitzer-IRAC Herschel-PACS...
Dust offers a unique probe of the interstellar medium (ISM) across multiple size, density, and temperature scales. is detected in outflows evolved stars, star-forming molecular clouds, planet-forming disks, even galaxies at dawn Universe. These grains also have profound effect on various astrophysical phenomena from thermal balance extinction to building blocks for planets, changes dust grain properties will affect all these phenomena. A full understanding its forms stages requires...
Abstract We present our fifth set of results from mid-infrared imaging survey Milky Way Giant H ii (GH ) regions with detailed analysis DR7 and K3-50. obtained 20/25 37 μ m maps both using the FORCAST instrument on Stratospheric Observatory For Infrared Astronomy. investigate multiscale properties K3-50 data in conjunction previous multiwavelength observations. Near- to far-infrared spectral energy distributions individual compact infrared sources were constructed fitted massive young...