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We report 850 μ m continuum polarization observations toward the filamentary high-mass star-forming region NGC 2264, taken as part of the B -fields In STar forming Regions Observations large program on the James Clerk Maxwell Telescope. These data reveal a well-structured nonuniform magnetic field in the NGC 2264C and 2264D regions with a prevailing orientation around 30° from north to east. Field strength estimates and a virial analysis of the major clumps indicate that NGC 2264C is globally dominated by gravity, while in 2264D, magnetic, gravitational, and kinetic energies are roughly balanced. We present an analysis scheme that utilizes the locally resolved magnetic field structures, together with the locally measured gravitational vector field and the extracted filamentary network. From this, we infer statistical trends showing that this network consists of two main groups of filaments oriented approximately perpendicular to one another. Additionally, gravity shows one dominating converging direction that is roughly perpendicular to one of the filament orientations, which is suggestive of mass accretion along this direction. Beyond these statistical trends, we identify two types of filaments. The type I filament is perpendicular to the magnetic field with local gravity transitioning from parallel to perpendicular to the magnetic field from the outside to the filament ridge. The type II filament is parallel to the magnetic field and local gravity. We interpret these two types of filaments as originating from the competition between radial collapsing, driven by filament self-gravity, and longitudinal collapsing, driven by the region's global gravity.

We present observations of polarized dust emission at 850 μ m from the L43 molecular cloud, which sits in the Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope as a part of the BISTRO large program. L43 is a dense ( ${N}_{{{\rm{H}}}_{2}}\sim {10}^{22}$ –10 ^23 cm ^−2 ) complex molecular cloud with a submillimeter-bright starless core and two protostellar sources. There appears to be an evolutionary gradient along the isolated filament that L43 is embedded within, with the most evolved source closest to the Sco OB2 association. One of the protostars drives a CO outflow that has created a cavity to the southeast. We see a magnetic field that appears to be aligned with the cavity walls of the outflow, suggesting interaction with the outflow. We also find a magnetic field strength of up to ∼160 ± 30 μ G in the main starless core and up to ∼90 ± 40 μ G in the more diffuse, extended region. These field strengths give magnetically super- and subcritical values, respectively, and both are found to be roughly trans-Alfvénic. We also present a new method of data reduction for these denser but fainter objects like starless cores.

We study the H ii regions associated with the NGC 6334 molecular cloud observed in the submillimeter and taken as part of the B -fields In STar-forming Region Observations Survey. In particular, we investigate the polarization patterns and magnetic field morphologies associated with these H ii regions. Through polarization pattern and pressure calculation analyses, several of these bubbles indicate that the gas and magnetic field lines have been pushed away from the bubble, toward an almost tangential (to the bubble) magnetic field morphology. In the densest part of NGC 6334, where the magnetic field morphology is similar to an hourglass, the polarization observations do not exhibit observable impact from H ii regions. We detect two nested radial polarization patterns in a bubble to the south of NGC 6334 that correspond to the previously observed bipolar structure in this bubble. Finally, using the results of this study, we present steps (incorporating computer vision; circular Hough transform) that can be used in future studies to identify bubbles that have physically impacted magnetic field lines.

We present BISTRO Survey 850 μ m dust emission polarization observations of the L1495A-B10 region of the Taurus molecular cloud, taken at the James Clerk Maxwell Telescope (JCMT). We observe a roughly triangular network of dense filaments. We detect nine of the dense starless cores embedded within these filaments in polarization, finding that the plane-of-sky orientation of the core-scale magnetic field lies roughly perpendicular to the filaments in almost all cases. We also find that the large-scale magnetic field orientation measured by Planck is not correlated with any of the core or filament structures, except in the case of the lowest-density core. We propose a scenario for early prestellar evolution that is both an extension to, and consistent with, previous models, introducing an additional evolutionary transitional stage between field-dominated and matter-dominated evolution, observed here for the first time. In this scenario, the cloud collapses first to a sheet-like structure. Uniquely, we appear to be seeing this sheet almost face on. The sheet fragments into filaments, which in turn form cores. However, the material must reach a certain critical density before the evolution changes from being field dominated to being matter dominated. We measure the sheet surface density and the magnetic field strength at that transition for the first time and show consistency with an analytical prediction that had previously gone untested for over 50 yr.

Gas source molecular beam epitaxy/migration enhanced epitaxy (MBE/MEE) is used in the growth of InAs/AlSb superlattices. In and Sb atoms are replaced, and found to be moving continuously toward the surface during gas source MEE growth, as revealed by reflection high energy electron diffraction observations. Replacement and movement are caused by the bonding strength of InSb, which is very weak. A reduction in growth temperature causes the lowering of movement of Indium atoms.

We report ALMA observations of [C I](³P1 - ³P0), 13CO, and C18O(J = 1-0) toward the central region of a nearby Seyfert galaxy NGC 613. The very high resolutions of 0.26 x 0.23 (=22 x 20 pc) for [C I] and 0.42 x 0.35 (=36 x 30 pc) for 13CO, and C18O resolve the circumnuclear disk (CND) and star-forming ring. The distribution of [C I] in the ring resembles that of the CO emission, although [C I] is prominent in the CND. This can be caused by the low intensities of the CO isotopes due to the low optical depths under the high temperature in the CND.We found that the intensity ratios of [C I] to 12CO(3-2) (RC I/CO) and to 13CO(1-0) (RC I/13CO) are high at several positions around the edge of the ring. The spectral profiles of CO lines mostly correspond each other in the spots of the ring and high RC I/CO, but those of [CI] at spots of high RC I/CO are different from those of CO. These results indicate that [CI] at the high RC I/CO traces different gas from that traced by the CO lines. The [C I] kinematics along the minor axis of NGC 613 could be interpreted as a bubbly molecular outflow. The outflow rate of molecular gas is higher than star formation rate in the CND. The flow could be mainly boosted by the active galactic nucleus through its radio jets. [ABSTRACT FROM AUTHOR]

We report ALMA observations of molecular gas and continuum emission in the 90 and 350 GHz bands toward a nearby Seyfert galaxy, NGC 613. Radio continuum emissions were detected at 95 and 350 GHz from both the circumnuclear disk (CND) (r≲ 90 pc) and a star-forming ring (250≲ r≲ 340 pc), and the 95 GHz continuum was observed to extend from the center at a position angle of 20° ± 8°. The archival 4.9 GHz data and our 95 GHz data show spectral indices of α≲-0.6 and -0.2 alongthe jets andinthe star-forming ring; these can be produced by synchrotron emission and free-free emission, respectively. In addition, we detected the emission of CO(3-2), HCN(1-0), HCN(4-3), HCO+(1-0), HCO+(4-3), CS(2-1), and CS(7-6) in both the CND and the ring. The rotational temperatures and column densities of molecules derived from J = 1-0 and 4-3 lines of HCN and HCO+ and J = 2-1 and 7-6 of CS in the CND and ring were derived. Furthermore, a non-local thermodynamic equilibrium model revealed that the kinetic temperature of Tk = 350-550 K in the CND is higher than Tk = 80-300 K in the ring, utilizing the intensity ratios of HCN, HCO+, and CS. The star-formation efficiency in the CND is almost an order of magnitude lower than those at the spots in the star-forming ring, while the dominant activity of the central region is star formation rather than active galactic nuclei.We determined that the large velocity dispersion of CO extending towards the north side of the CND and decomposing into blueshifted and redshifted features is probably explained by the effect of the radio jets. These results strongly suggest that the jets heat the gas in the CND, in which the feedback prevents star formation. [ABSTRACT FROM AUTHOR]

We present survey data of six NH3 (J, K) = (1, 1), (2, 2), (3, 3), (4, 4), (5, 5), and (6, 6) lines, simultaneously observed with the Tsukuba 32m telescope, in the main part of the central molecular zone of the Galaxy. The total number of on-source positions was 2655. The three lower transitions were detected with S/N > 3 at 2323 positions (93% of all the on-source positions). Among 2323, the S/N's of (J, K) = (4, 4), (5, 5), and (6, 6) exceeded 3.0 at 1426(54%), 1150(43%), and 1359(51%) positions, respectively. Simultaneous observations of the lines enabled us to accurately derive intensity ratios with less systematic errors. Boltzmann plots indicate that there are two temperature components: cold (~20 K) and warm (~100 K). Typical intensity ratios of Tmb (2, 2)/Tmb (1, 1), Tmb (4, 4)/Tmb (2, 2), Tmb (5, 5)/Tmb (4, 4), and Tmb (6, 6)/Tmb (3, 3) were 0.71, 0.45, 0.65, and 0.17, respectively. These line ratios correspond to the diversity of the rotational temperature, which results from mixing of the two temperature components. [ABSTRACT FROM AUTHOR]

We have mapped the Orion-A giant molecular cloud in the CO(J=4-3) line with the Tsukuba 30cm submillimeter telescope. The map covered a 7.125 deg2 area with a 9' resolution, including main components of the cloud such as the Orion Nebula, OMC- 2/3, and L1641-N. The most intense emission was detected toward the Orion KL region. The integrated intensity ratio between CO(J=4-3) and CO(J=1-0) was derived using data from the Columbia-Universidad de Chile CO survey, which was carried out with a comparable angular resolution. The ratio was r4−3/1−0 ∼0.2 in the southern region of the cloud and 0.4-0.8 at star forming regions. We found a trend that the ratio shows higher values at the edges of the cloud. In particular, the ratio at the northeastern edge of the cloud at (l, b) ≈ (208. ° 375, −19. ° 0) shows the highest value of 1.1. The physical condition of the molecular gas in the cloud was estimated by non-LTE calculation. The result indicates that the kinetic temperature has a gradient from north (Tkin = 80 K) to south (20 K). The estimation shows that the gas associated with the edge of the cloud is warm (Tkin ∼60 K), dense (nH2 ∼ 104 cm−3), and optically thin, which may be explained by heating and sweeping of interstellar materials from OB clusters. [ABSTRACT FROM AUTHOR]

Recent X-ray studies have revealed overionized recombining plasmas in a dozen mixed-morphology (MM) supernova remnants (SNRs). However, the physical process of the overionization has not yet been fully understood. Here we report on spatially resolved spectroscopy of X-ray emission from W44, one of the overionized MM SNRs, using XMM-Newton data from deep observations, with the aim of clarifying the physical origin of the overionization. We find that combination of low electron temperature and low recombination timescale is achieved in the region interacting with dense molecular clouds. Moreover, a clear anticorrelation between the electron temperature and the recombination timescale is obtained from each of the regions with and without the molecular clouds. The results are well explained if the plasma was overionized by rapid cooling through thermal conduction with the dense clouds hit by the blast wave of W44. Given that a few other overionized SNRs show evidence for adiabatic expansion as the major driver of the rapid cooling, our new result indicates that both processes can contribute to overionization in SNRs, with the dominant channel depending on the evolutionary stage. [ABSTRACT FROM AUTHOR]

We present [C i] , 12CO, 13CO, and C18O () observations of the central region (radius 1 kpc) of the starburst galaxy NGC 1808 at 30–50 pc resolution conducted with the Atacama Large Millimeter/submillimeter Array. Radiative transfer analysis of multiline data indicates warm ( K) and dense ( cm−3) molecular gas with high column density of atomic carbon ( cm−2) in the circumnuclear disk (central 100 pc). The C i/H2 abundance in the central 1 kpc is , consistent with the values in luminous infrared galaxies. The intensity ratios of [C i]/CO (1–0) and [C i]/CO (3–2), respectively, decrease and increase with radius in the central 1 kpc, whereas [C i]/CO (2–1) is uniform within statistical errors. The result can be explained by excitation and optical depth effects, since the effective critical density of CO (2–1) is comparable to that of [C i]. The distribution of [C i] is similar to that of 13CO (2–1), and the ratios of [C i] to 13CO (2–1) and C18O (2–1) are uniform within in the central pc starburst disk. The results suggest that [C i] luminosity can be used as a CO-equivalent tracer of molecular gas mass, although caution is needed when applied in resolved starburst nuclei (e.g., circumnuclear disk), where the [C i]/CO (1–0) luminosity ratio is enhanced owing to high excitation and atomic carbon abundance. The [C i]/CO (1–0) intensity ratio toward the base of the starburst-driven outflow is , and the upper limits of the mass and kinetic energy of the atomic carbon outflow are and , respectively. [ABSTRACT FROM AUTHOR]