Author: "Coude, S." - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Coude, S."' showing total 46 results

Start Over Author "Coude, S."

46 results on '"Coude, S."'

1. The JCMT BISTRO Survey: Multi-wavelength polarimetry of bright regions in NGC 2071 in the far-infrared/submillimetre range, with POL-2 and HAWC+

Author: Fanciullo, L., Kemper, F., Pattle, K., Koch, P. M., Sadavoy, S., Coudé, S., Soam, A., Hoang, T., Onaka, T., Gouellec, V. J. M. Le, Arzoumanian, D., Berry, D., Eswaraiah, C., Chung, E. J., Furuya, R., Hull, C. L. H., Hwang, J., Johnstone, D., Kang, J. -h., Kim, K. H., Kirchschlager, F., Könyves, V., Kwon, J., Kwon, W., Lai, S. -P., Lee, C. W., Liu, T., Lyo, A. -R., Stephens, I., Tamura, M., Tang, X., Ward-Thompson, D., Whitworth, A., and Shinnaga, H.
Subjects: Astrophysics - Astrophysics of Galaxies
Abstract: Polarized dust emission is a key tracer in the study of interstellar medium and of star formation. The observed polarization, however, is a product of magnetic field structure, dust grain properties and grain alignment efficiency, as well as their variations in the line of sight, making it difficult to interpret polarization unambiguously. The comparison of polarimetry at multiple wavelengths is a possible way of mitigating this problem. We use data from HAWC+/SOFIA and from SCUBA-2/POL-2 (from the BISTRO survey) to analyse the NGC 2071 molecular cloud at 154, 214 and 850 $\mu$m. The polarization angle changes significantly with wavelength over part of NGC 2071, suggesting a change in magnetic field morphology on the line of sight as each wavelength best traces different dust populations. Other possible explanations are the existence of more than one polarization mechanism in the cloud or scattering from very large grains. The observed change of polarization fraction with wavelength, and the 214-to-154 $\mu$m polarization ratio in particular, are difficult to reproduce with current dust models under the assumption of uniform alignment efficiency. We also show that the standard procedure of using monochromatic intensity as a proxy for column density may produce spurious results at HAWC+ wavelengths. Using both long-wavelength (POL-2, 850 $\mu$m) and short-wavelength (HAWC+, $\lesssim 200\, \mu$m) polarimetry is key in obtaining these results. This study clearly shows the importance of multi-wavelength polarimetry at submillimeter bands to understand the dust properties of molecular clouds and the relationship between magnetic field and star formation., Comment: Main article: 18 pages, 11 figures. Online supplemental material: 2 pages, 3 figures
Published: 2022
Full Text: View/download PDF

2. Dust polarized emission observations of NGC 6334; BISTRO reveals the details of the complex but organized magnetic field structure of the high-mass star-forming hub-filament network

Author: Arzoumanian, D., Furuya, R., Hasegawa, T., Tahani, M., Sadavoy, S., Hull, C. L. H., Johnstone, D., Koch, P. M., Inutsuka, S. -i., Doi, Y., Hoang, T., Onaka, T., Iwasaki, K., Shimajiri, Y., Inoue, T., Peretto, N., André, P., Bastien, P., Berry, D., Chen, H. -R. V., Di Francesco, J., Eswaraiah, C., Fanciullo, L., Fissel, L. M., Hwang, J., Kang, J. -h., Kim, G., Kim, K. -T., Kirchschlager, F., Kwon, W., Lee, C. W., Liu, H. -L., Lyo, A. -R., Pattle, K., Soam, A., Tang, X., Whitworth, A., Ching, T. -C., Coudé, S., Wang, J. -W., Ward-Thompson, D., Lai, S. -P., Qiu, K., Bourke, T. L., Byun, D. -Y., Chen, M., Chen, Z., Chen, W. P., Cho, J., Choi, Y., Choi, M., Chrysostomou, A., Chung, E. J., Dai, S., Diep, P. N., Duan, H. -Y., Duan, Y., Eden, D., Fiege, J., Franzmann, E., Friberg, P., Fuller, G., Gledhill, T., Graves, S., Greaves, J., Griffin, M., Gu, Q., Han, I., Hatchell, J., Hayashi, S., Houde, M., Jeong, I. -G., Kang, M., Kang, S. -j., Kataoka, A., Kawabata, K., Kemper, F., Kim, M. -R., Kim, K. H., Kim, J., Kim, S., Kirk, J., Kobayashi, M. I. N., Konyves, V., Kusune, T., Kwon, J., Lacaille, K., Law, C. -Y., Lee, C. -F., Lee, Y. -H., Lee, S. -S., Lee, H., Lee, J. -E., Li, H. -b., Li, D., Liu, J., Liu, T., Liu, S. -Y., Lu, X., Mairs, S., Matsumura, M., Matthews, B., Moriarty-Schieven, G., Nagata, T., Nakamura, F., Nakanishi, H., Ngoc, N. B., Ohashi, N., Park, G., Parsons, H., Pyo, T. -S., Qian, L., Rao, R., Rawlings, J., Rawlings, M., Retter, B., Richer, J., Rigby, A., Saito, H., Savini, G., Scaife, A., Seta, M., Shinnaga, H., Tamura, M., Tang, Y. -W., Tomisaka, K., Tram, L. N., Tsukamoto, Y., Viti, S., Wang, H., Xie, J., Yen, H. -W., Yoo, H., Yuan, J., Yun, H. -S., Zenko, T., Zhang, G., Zhang, C. -P., Zhang, Y., Zhou, J., Zhu, L., de Looze, I., Dowell, C. D., Eyres, S., Falle, S., Friesen, R., Robitaille, J. -F., and van Loo, S.
Subjects: Astrophysics - Astrophysics of Galaxies
Abstract: [Abridged] Filaments and hubs have received special attention recently thanks to studies showing their role in star formation. While the column density and velocity structures of both filaments and hubs have been studied, their magnetic fields (B-field) are not yet characterized. We aim to understand the role of the B-field in the dynamical evolution of the NGC 6334 hub-filament network. We present new observations of the dust polarized emission at 850$\mu$m towards NGC 6334 obtained with the JCMT/POL-2. We study the distribution and dispersion of the polarized intensity ($PI$), the polarization fraction ($PF$), and the B-field angle ($\theta_{B}$). We derive the power spectrum of the intensity and $\theta_{B}$ along the ridge crest. Our analyses show a complex B-field structure when observed over the whole region ($\sim10$ pc), however, at smaller scales ($\sim1$ pc), $\theta_{B}$ varies coherently along the filaments. The observed power spectrum of $\theta_{B}$ can be well represented with a power law function with a slope $-1.33\pm0.23$, which is $\sim20\%$ shallower than that of $I$. This result is compatible with the properties of simulated filaments and may indicate the processes at play in the formation of filaments. $\theta_{B}$ rotates from being mostly perpendicular to the filament crests to mostly parallel as they merge with the hubs. This variation of $\theta_{B}$ may be tracing local velocity flows of matter in-falling onto the hubs. Our analysis suggests a variation of the energy balance along the crests of these filaments, from magnetically critical/supercritical at their far ends to magnetically subcritical near the hubs. We detect an increase of $PF$ towards the high-column density star cluster-forming hubs that may result from the increase of grain alignment efficiency due to stellar radiation from the newborn stars., Comment: Accepted for publication in Astronomy & Astrophysics
Published: 2020
Full Text: View/download PDF

3. SOFIA Community Science I: HAWC+ Polarimetry of 30 Doradus

Author: Gordon, M. S., Lopez-Rodriguez, E., Andersson, B. -G., Clarke, M., Coude, S., Moullet, A., Richards, S. N., Shuping, R. Y., Vacca, W., and Yorke, H.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a Boeing 747SP aircraft modified to accommodate a 2.7 meter gyro-stabilized telescope, which is mainly focused to studying the Universe at infrared wavelengths. As part of the Strategic Director's Discretionary Time (S-DDT) program, SOFIA performs observations of relevant science cases and immediately offers science-ready data products to the astronomical community. We present the first data release of the S-DDT program on far-infrared imaging polarimetric observations of 30 Doradus using the High-resolution Airborne Wideband Camera-Plus (HAWC+) at 53, 89, 154, and 214 micron. We present the status and quality of the observations, an overview of the SOFIA data products, and examples of working with HAWC+ polarimetric data that will enhance the scientific analysis of this, and future, data sets. These observations illustrate the potential influence of magnetic fields and turbulence in a star-forming region within the Tarantula Nebula., Comment: SOFIA Science Center White Paper, 20 pages, 14 figures, 3 tables
Published: 2018

4. The JCMT Gould Belt Survey: A First Look at the Auriga-California Molecular Cloud with SCUBA-2

Author: Broekhoven-Fiene, H., Matthews, B. C., Harvey, P., Kirk, H., Chen, M., Currie, M. J., Pattle, K., Lane, J., Buckle, J., Di Francesco, J., Drabek-Maunder, E., Johnstone, D., Berry, D. S., Fich, M., Hatchell, J., Jenness, T., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Astrophysics of Galaxies
Abstract: We present 850 and 450 micron observations of the dense regions within the Auriga-California molecular cloud using SCUBA-2 as part of the JCMT Gould Belt Legacy Survey to identify candidate protostellar objects, measure the masses of their circumstellar material (disk and envelope), and compare the star formation to that in the Orion A molecular cloud. We identify 59 candidate protostars based on the presence of compact submillimeter emission, complementing these observations with existing Herschel/SPIRE maps. Of our candidate protostars, 24 are associated with young stellar objects (YSOs) in the Spitzer and Herschel/PACS catalogs of 166 and 60 YSOs, respectively (177 unique), confirming their protostellar nature. The remaining 35 candidate protostars are in regions, particularly around LkHalpha 101, where the background cloud emission is too bright to verify or rule out the presence of the compact 70 micron emission that is expected for a protostellar source. We keep these candidate protostars in our sample but note that they may indeed be prestellar in nature. Our observations are sensitive to the high end of the mass distribution in Auriga-Cal. We find that the disparity between the richness of infrared star forming objects in Orion A and the sparsity in Auriga-Cal extends to the submillimeter, suggesting that the relative star formation rates have not varied over the Class II lifetime and that Auriga-Cal will maintain a lower star formation efficiency., Comment: 39 pages (54 including the Appendix), 9 figures, 3 tables, in press in ApJ
Published: 2018
Full Text: View/download PDF

5. The JCMT Gould Belt Survey: A First Look at IC 5146

Author: Johnstone, D., Ciccone, S., Kirk, H., Mairs, S., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Hatchell, J., Jenness, T., Mottram, J. C., Pattle, K., Di Francesco, S. Tisi J., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fich, M., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Nutter, D., Pineda, J. E., Salji, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract: We present 450 and 850 micron submillimetre continuum observations of the IC5146 star-forming region taken as part of the JCMT Gould Belt Survey. We investigate the location of bright submillimetre (clumped) emission with the larger-scale molecular cloud through comparison with extinction maps, and find that these denser structures correlate with higher cloud column density. Ninety-six individual submillimetre clumps are identified using FellWalker and their physical properties are examined. These clumps are found to be relatively massive, ranging from 0.5to 116 MSun with a mean mass of 8 MSun and a median mass of 3.7 MSun. A stability analysis for the clumps suggest that the majority are (thermally) Jeans stable, with M/M_J < 1. We further compare the locations of known protostars with the observed submillimetre emission, finding that younger protostars, i.e., Class 0 and I sources, are strongly correlated with submillimetre peaks and that the clumps with protostars are among the most Jeans unstable. Finally, we contrast the evolutionary conditions in the two major star-forming regions within IC5146: the young cluster associated with the Cocoon Nebula and the more distributed star formation associated with the Northern Streamer filaments. The Cocoon Nebula appears to have converted a higher fraction of its mass into dense clumps and protostars, the clumps are more likely to be Jeans unstable, and a larger fraction of these remaining clumps contain embedded protostars. The Northern Streamer, however, has a larger number of clumps in total and a larger fraction of the known protostars are still embedded within these clumps., Comment: 30 pages, 11 figures, 8 tables, accepted by ApJ
Published: 2017
Full Text: View/download PDF

6. The JCMT Gould Belt Survey: A First Look at Southern Orion A with SCUBA-2

Author: Mairs, Steve, Johnstone, D., Kirk, H., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Graves, S., Hatchell, J., Jenness, T., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Salji, C., Di Francesco, J., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coudé, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract: We present the JCMT Gould Belt Survey's first look results of the southern extent of the Orion A Molecular Cloud ($\delta \leq -5\mathrm{:}31\mathrm{:}27.5$). Employing a two-step structure identification process, we construct individual catalogues for large-scale regions of significant emission labelled as islands and smaller-scale subregions called fragments using the 850 $\mu$m continuum maps obtained using SCUBA-2. We calculate object masses, sizes, column densities, and concentrations. We discuss fragmentation in terms of a Jeans instability analysis and highlight interesting structures as candidates for follow-up studies. Furthermore, we associate the detected emission with young stellar objects (YSOs) identified by Spitzer and Herschel. We find that although the population of active star-forming regions contains a wide variety of sizes and morphologies, there is a strong positive correlation between the concentration of an emission region and its calculated Jeans instability. There are, however, a number of highly unstable subregions in dense areas of the map that show no evidence of star formation. We find that only $\sim$72\% of the YSOs defined as Class 0+I and flat-spectrum protostars coincide with dense 850 $\mu$m emission structures (column densities $>3.7\times10^{21}\mathrm{\:cm}^{-2}$). The remaining 28\% of these objects, which are expected to be embedded in dust and gas, may be misclassified. Finally, we suggest that there is an evolution in the velocity dispersion of young stellar objects such that sources which are more evolved are associated with higher velocities., Comment: 31 Pages, 19 Figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS)
Published: 2016
Full Text: View/download PDF

7. The JCMT Gould Belt Survey: Evidence for Dust Grain Evolution in Perseus Star-forming Clumps

Author: Chen, Michael Chun-Yuan, Di Francesco, J., Johnstone, D., Sadavoy, S., Hatchell, J., Mottram, J. C., Kirk, H., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Pezzuto, S., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Schneider-Bontemps, N., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract: The dust emissivity spectral index, $\beta$, is a critical parameter for deriving the mass and temperature of star-forming structures, and consequently their gravitational stability. The $\beta$ value is dependent on various dust grain properties, such as size, porosity, and surface composition, and is expected to vary as dust grains evolve. Here we present $\beta$, dust temperature, and optical depth maps of the star-forming clumps in the Perseus Molecular Cloud determined from fitting SEDs to combined Herschel and JCMT observations in the 160 $\mu$m, 250 $\mu$m, 350 $\mu$m, 500 $\mu$m, and 850 $\mu$m bands. Most of the derived $\beta$, and dust temperature values fall within the ranges of 1.0 - 2.7 and 8 - 20 K, respectively. In Perseus, we find the $\beta$ distribution differs significantly from clump to clump, indicative of grain growth. Furthermore, we also see significant, localized $\beta$ variations within individual clumps and find low $\beta$ regions correlate with local temperature peaks, hinting at the possible origins of low $\beta$ grains. Throughout Perseus, we also see indications of heating from B stars and embedded protostars, as well evidence of outflows shaping the local landscape., Comment: Accepted to ApJ, 15 figures, 3 tables
Published: 2016
Full Text: View/download PDF

8. The JCMT Gould Belt Survey: Evidence for radiative heating and contamination in the W40 complex

Author: Rumble, D., Hatchell, J., Pattle, K., Kirk, H., Wilson, T., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract: We present SCUBA-2 450{\mu}m and 850{\mu}m observations of the W40 complex in the Serpens-Aquila region as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) of nearby star-forming regions. We investigate radiative heating by constructing temperature maps from the ratio of SCUBA-2 fluxes using a fixed dust opacity spectral index, {\beta} = 1.8, and a beam convolution kernel to achieve a common 14.8" resolution. We identify 82 clumps ranging between 10 and 36K with a mean temperature of 20{\pm}3K. Clump temperature is strongly correlated with proximity to the external OB association and there is no evidence that the embedded protostars significantly heat the dust. We identify 31 clumps that have cores with densities greater than 105cm{^{-3}}. Thirteen of these cores contain embedded Class 0/I protostars. Many cores are associated with bright-rimmed clouds seen in Herschel 70 {\mu}m images. From JCMT HARP observations of the 12CO 3-2 line, we find contamination of the 850{\mu}m band of up to 20 per cent. We investigate the free-free contribution to SCUBA-2 bands from large-scale and ultracompact H ii regions using archival VLA data and find the contribution is limited to individual stars, accounting for 9 per cent of flux per beam at 450 {\mu}m or 12 per cent at 850 {\mu}m in these cases. We conclude that radiative heating has potentially influenced the formation of stars in the Dust Arc sub-region, favouring Jeans stable clouds in the warm east and fragmentation in the cool west., Comment: 27 pages, 25 figures, 7 tables, 3 online catalogues
Published: 2016
Full Text: View/download PDF

9. The JCMT Gould Belt Survey: the effect of molecular contamination in SCUBA-2 observations of Orion A

Author: Coudé, S., Bastien, P., Kirk, H., Johnstone, D., Drabek-Maunder, E., Graves, S., Hatchell, J., Chapin, E. L., Gibb, A. G., and Matthews, B.
Subjects: Astrophysics - Astrophysics of Galaxies
Abstract: Thermal emission from cold dust grains in giant molecular clouds can be used to probe the physical properties, such as density, temperature and emissivity in star-forming regions. We present the SCUBA-2 shared-risk observations at 450 $\mu$m and 850 $\mu$m of the Orion A molecular cloud complex taken at the James Clerk Maxwell Telescope (JCMT). Previous studies showed that molecular emission lines can contribute significantly to the measured fluxes in those continuum bands. We use the HARP $^{12}$CO J=3-2 integrated intensity map for Orion A in order to evaluate the molecular line contamination and its effects on the SCUBA-2 maps. With the corrected fluxes, we have obtained a new spectral index $\alpha$ map for the thermal emission of dust in the well-known integral-shaped filament. Furthermore, we compare a sample of 33 sources, selected over the Orion A molecular cloud complex for their high $^{12}$CO J=3-2 line contamination, to 27 previously identified clumps in OMC-4. This allows us to quantify the effect of line contamination on the ratio of 850 $\mu$m to 450 $\mu$m flux densities and how it modifies the deduced spectral index of emissivity $\beta$ for the dust grains. We also show that at least one Spitzer-identified protostellar core in OMC-5 has a $^{12}$CO J=3-2 contamination level of 16 %. Furthermore, we find the strongest contamination level (44 %) towards a young star with disk near OMC-2. This work is part of the JCMT Gould Belt Legacy Survey., Comment: 13 pages, 6 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS)
Published: 2016
Full Text: View/download PDF

10. The JCMT Gould Belt Survey: A First Look at Dense Cores in Orion B

Author: Kirk, H., Di Francesco, J., Johnstone, D., Duarte-Cabral, A., Sadavoy, S., Hatchell, J., Mottram, J. C., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract: We present a first look at the SCUBA-2 observations of three sub-regions of the Orion B molecular cloud: LDN 1622, NGC 2023/2024, and NGC 2068/2071, from the JCMT Gould Belt Legacy Survey. We identify 29, 564, and 322 dense cores in L1622, NGC 2023/2024, and NGC 2068/2071 respectively, using the SCUBA-2 850 micron map, and present their basic properties, including their peak fluxes, total fluxes, and sizes, and an estimate of the corresponding 450 micron peak fluxes and total fluxes, using the FellWalker source extraction algorithm. Assuming a constant temperature of 20 K, the starless dense cores have a mass function similar to that found in previous dense core analyses, with a Salpeter-like slope at the high-mass end. The majority of cores appear stable to gravitational collapse when considering only thermal pressure; indeed, most of the cores which have masses above the thermal Jeans mass are already associated with at least one protostar. At higher cloud column densities, above 1-2 x 10^23 cm^-2, most of the mass is found within dense cores, while at lower cloud column densities, below 1 x 10^23 cm^-2, this fraction drops to 10% or lower. Overall, the fraction of dense cores associated with a protostar is quite small (<8%), but becomes larger for the densest and most centrally concentrated cores. NGC 2023 / 2024 and NGC 2068/2071 appear to be on the path to forming a significant number of stars in the future, while L1622 has little additional mass in dense cores to form many new stars., Comment: Accepted for publication in ApJ; 28 pages, 19 figures. Data associated with the paper, including the full table 4, can be found at https://doi.org/10.11570/16.0003
Published: 2015
Full Text: View/download PDF

11. The JCMT Gould Belt Survey: SCUBA-2 observations of circumstellar disks in L 1495

Author: Buckle, J. V., Drabek-Maunder, E., Greaves, J., Richer, J. S., Matthews, B. C., Johnstone, D., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Jenness, T., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Salji, C., Tisi, S., Di Francesco, J., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Moriarty-Schieven, G., Rawlings, J., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Astrophysics of Galaxies
Abstract: We present 850$\mu$m and 450$\mu$m data from the JCMT Gould Belt Survey obtained with SCUBA-2 and characterise the dust attributes of Class I, Class II and Class III disk sources in L1495. We detect 23% of the sample at both wavelengths, with the detection rate decreasing through the Classes from I--III. The median disk mask is 1.6$\times 10^{-3}$M$_{\odot}$, and only 7% of Class II sources have disk masses larger than 20 Jupiter masses. We detect a higher proportion of disks towards sources with stellar hosts of spectral type K than spectral type M. Class II disks with single stellar hosts of spectral type K have higher masses than those of spectral type M, supporting the hypothesis that higher mass stars have more massive disks. Variations in disk masses calculated at the two wavelengths suggests there may be differences in dust opacity and/or dust temperature between disks with hosts of spectral types K to those with spectral type M., Comment: 11 pages, 10 figures plus Appendix. MNRAS accepted
Published: 2015
Full Text: View/download PDF

12. The JCMT Gould Belt Survey: First results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population

Author: Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M. R., André, Ph., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Astrophysics of Galaxies
Abstract: In this paper we present the first observations of the Ophiuchus molecular cloud performed as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) with the SCUBA-2 instrument. We demonstrate methods for combining these data with previous HARP CO, Herschel, and IRAM N$_{2}$H$^{+}$ observations in order to accurately quantify the properties of the SCUBA-2 sources in Ophiuchus. We produce a catalogue of all of the sources found by SCUBA-2. We separate these into protostars and starless cores. We list all of the starless cores and perform a full virial analysis, including external pressure. This is the first time that external pressure has been included in this level of detail. We find that the majority of our cores are either bound or virialised. Gravitational energy and external pressure are on average of a similar order of magnitude, but with some variation from region to region. We find that cores in the Oph A region are gravitationally bound prestellar cores, while cores in the Oph C and E regions are pressure-confined. We determine that N$_{2}$H$^{+}$ is a good tracer of the bound material of prestellar cores, although we find some evidence for N$_{2}$H$^{+}$ freeze-out at the very highest core densities. We find that non-thermal linewidths decrease substantially between the gas traced by C$^{18}$O and that traced by N$_{2}$H$^{+}$, indicating the dissipation of turbulence at higher densities. We find that the critical Bonnor-Ebert stability criterion is not a good indicator of the boundedness of our cores. We detect the pre-brown dwarf candidate Oph B-11 and find a flux density and mass consistent with previous work. We discuss regional variations in the nature of the cores and find further support for our previous hypothesis of a global evolutionary gradient across the cloud from southwest to northeast, indicating sequential star formation across the region., Comment: 34 pages, 20 figures, 5 tables. Accepted for publication in MNRAS
Published: 2015
Full Text: View/download PDF

13. The JCMT Gould Belt Survey: Evidence for radiative heating in Serpens MWC 297 and its influence on local star formation

Author: Rumble, D., Hatchell, J., Gutermuth, R. A., Kirk, H., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M. R., Ward-Thompson, D., Allen, L. E., Cieza, L. A., Dunham, M. M., Harvey, P. M., Stapelfeldt, K. R., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Subjects: Astrophysics - Solar and Stellar Astrophysics
Abstract: We present SCUBA-2 450micron and 850micron observations of the Serpens MWC 297 region, part of the JCMT Gould Belt Survey of nearby star-forming regions. Simulations suggest that radiative feedback influences the star-formation process and we investigate observational evidence for this by constructing temperature maps. Maps are derived from the ratio of SCUBA-2 fluxes and a two component model of the JCMT beam for a fixed dust opacity spectral index of beta = 1.8. Within 40 of the B1.5Ve Herbig star MWC 297, the submillimetre fluxes are contaminated by free-free emission with a spectral index of 1.03+-0.02, consistent with an ultra-compact HII region and polar winds/jets. Contamination accounts for 73+-5 per cent and 82+-4 per cent of peak flux at 450micron and 850micron respectively. The residual thermal disk of the star is almost undetectable at these wavelengths. Young Stellar Objects are confirmed where SCUBA-2 850micron clumps identified by the fellwalker algorithm coincide with Spitzer Gould Belt Survey detections. We identify 23 objects and use Tbol to classify nine YSOs with masses 0.09 to 5.1 Msun. We find two Class 0, one Class 0/I, three Class I and three Class II sources. The mean temperature is 15+-2K for the nine YSOs and 32+-4K for the 14 starless clumps. We observe a starless clump with an abnormally high mean temperature of 46+-2K and conclude that it is radiatively heated by the star MWC 297. Jeans stability provides evidence that radiative heating by the star MWC 297 may be suppressing clump collapse., Comment: 24 pages, 13 figures, 7 tables
Published: 2014
Full Text: View/download PDF

14. Extragalactic Magnetism with SOFIA (SALSA Legacy Program). III. First Data Release and On-the-fly Polarization Mapping Characterization* * The SOFIA Legacy Program for Magnetic Fields in Galaxies (SALSA) provides a software repository at https://github.com/galmagfields/hawc and publicly available data at http://galmagfields.com

Author: Lopez-Rodriguez, E, Clarke, M, Shenoy, S, Vacca, W, Coude, S, Arneson, R, Ashton, P, Eftekharzadeh, S, Beck, R, Beckman, JE, Borlaff, AS, Clark, SE, Dale, DA, Martin-Alvarez, S, Ntormousi, E, Reach, WT, Roman-Duval, J, Tassis, K, Harper, DA, Marcum, PM, Lopez-Rodriguez, E [0000-0001-5357-6538], Vacca, W [0000-0002-9123-0068], Coude, S [0000-0002-0859-0805], Beckman, JE [0000-0001-5747-7086], Borlaff, AS [0000-0003-3249-4431], Clark, SE [0000-0002-7633-3376], Dale, DA [0000-0002-5782-9093], Martin-Alvarez, S [0000-0002-4059-9850], Ntormousi, E [0000-0002-4324-0034], Reach, WT [0000-0001-8362-4094], Roman-Duval, J [0000-0001-6326-7069], Tassis, K [0000-0002-8831-2038], and Apollo - University of Cambridge Repository
Subjects: Pediatric Research Initiative, 5101 Astronomical Sciences, 5109 Space Sciences, 51 Physical Sciences, 5107 Particle and High Energy Physics
Abstract: We describe the data processing of the Survey on extragALactic magnetiSm with SOFIA (SALSA Legacy Program). This first data release presents 33% (51.34 hr out of 155.7 hr, including overheads) of the total awarded time from 2020 January to 2021 December. Our observations were performed using the newly implemented on-the-fly mapping (OTFMAP) technique in the polarimetric mode. We present the pipeline steps to obtain homogeneously reduced high-level data products of polarimetric maps of galaxies for use in scientific analysis. Our approach has a general design and can be applied to sources smaller than the field of view of the HAWC+ array in any given band. We estimate that the OTFMAP polarimetric mode offers a reduction of observing overheads by a factor 2.34 and an improvement in sensitivity by a factor 1.80 when compared to the same on-source time polarimetric observations using the chopping and nodding mode. The OTFMAP is a significant optimization of the polarimetric mode of HAWC+, as it ultimately reduces the cost of operations of HAWC+/SOFIA by increasing the science collected per hour of observation up to an overall factor of 2.49. The OTFMAP polarimetric mode is the standard observing strategy of SALSA. The results and quantitative analysis of this first data release are presented in Papers IV and V of the series.
Published: 2022
Full Text: View/download PDF

15. SPICA: the next observatory class infrared space astronomy mission

Author: Naylor, David, Abraham, Roberto, Bannister, M., Baum, Stefi, Cami, Jan, Chapman, Scott, Coude, S., Di Francesco, James, Fissel, Laura, Haggard, Daryl, Halpern, Mark, Houde, Martin, Hutchings, John, Johnstone, Doug, Joncas, Gilles, Matthews, Brenda, Metchev, Stan, O'Dea, Chris, Peeters, Els, Plume, Reme, Rosolowsky, Erik, Sadavoy, Sarah, Sawicki, Marcin, Scott, Doug, Sivakoff, Greg, Spencer, Locke, and Wilson, Christine
Subjects: astrophysics
Abstract: Over the last 40 years enormous advances have been made in infrared astronomy. Virtually all of these can be traced to the use of space-based telescopes, which avoid the deleterious effects of the earth’s atmosphere, and continued improvements in detector sensitivity and instrument design. Since its initial and modest contributions to previous infrared space astronomy missions, starting with ISO through to Herschel, Canada has grown in stature and is now recognized as a partner of choice by leading space agencies and scientific consortia embarking on the next generation of IR space astronomy missions. This white paper reviews the history of Canada’s contributions to IR space astronomy missions and presents the case for Canadian participation in the ESA-JAXA SPICA mission, which has been selected as one of three finalists for ESA’s fifth medium class mission, M5. Observations at far-infrared (FIR) wavelengths are optimal, not only for exploring galaxy formation in the farthest reaches of the Universe, but also star formation in our own Galaxy. Indeed, the study of cold and/or enshrouded systems can only be observed in the FIR. In essence, this provides the rationale for all space astronomy missions from IRAS through to Herschel. By any measure, Herschel was an outstanding success. It has caused astronomers to re-examine their theories of star formation and provided our first large scale view of distant star forming galaxies. With the SPICA telescope actively cooled to ~8 K, the lower thermal background will enable sensitivities two to three orders of magnitude better than Herschel’s! This sensitivity increase will allow SPICA not only to label photons by their wavelength over a volume of the Universe somewhere between one and ten thousand times greater than observed with Herschel, but also, and for the first time, allow it to label photons by their polarization in our Galaxy. Together these improvements augur major advances in the field. The SPICA instrument suite consists of three independent instruments: SAFARI – a FIR spectrometer; SMI – a mid-Infrared camera and spectrometer; and B-BOP - a FIR imaging polarimeter. The key features of each instrument are presented. Canadian scientific, technical and strategic leadership in the SPICA mission is well established. As a founding member of the SPICA/SAFARI consortium, Canada not only has much greater visibility and influence on the project, but also has the opportunity to contribute high-profile flight hardware to the mission. One of the primary tasks of the initial CSA-funded SPICA SAFARI Study was to identify and leverage Canadian signature technologies to establish a potential role for Canada in SPICA. As a result of the work undertaken over the last decade, Canada has the opportunity to deliver the high-resolution spectrometer component of the SAFARI instrument; one of three critical components of SAFARI which lies at its very heart. It is key to two of the main science drivers of the mission: i) galaxy evolution through spectral measurements of galaxies at high-redshift, and; ii) disk evolution by disentangling the line and continuum components of emission from spectral measurements of disks. Both of these fields of study are areas of excellence in Canadian astronomy. Several members of the team have a wealth of experience from science exploitation of Herschel data, some playing leading roles in Herschel key projects and many have been involved in developing the science cases for SPICA. All stand ready to assume leadership roles once the mission is selected by ESA and receives mission funding from the CSA. The impact on Canadian science, in terms of return on investment by the involvement of Canadian astronomers in science exploitation with SPICA through access to the guaranteed time will be over twice that of Herschel, which was one of, if not the, highest ROI of any CSA-funded space astronomy missions. Over the last decade Canada will have invested over $5M to establish a leading role in SPICA and as a result is now positioned to build the mission critical, high-resolution spectrometer for what will be the leading infrared observatory of the next decade if it is selected by ESA in 2021. At that time, Canada will have to make a decision on whether it will sign up for the mission. This point will be the last off-ramp for any nation in the SPICA consortium. Perhaps the greatest risk at an agency level is to diminish the trust that ESA has in the CSA as a dependable partner after staying the course for over a decade. ESA will hold the Mission Selection Review, to pick the winner of the three M5 finalists in April 2021. Programmatically, a letter will be required before this date (early 2021) from the CSA to ESA effectively stating that if ESA chooses SPICA, Canada is committed to the project. Securing mission funding requires approval from the Treasury Board of Canada. A strong statement of endorsement for SPICA in the LRP is a necessary prerequisite., White paper identifier W049
Published: 2019
Full Text: View/download PDF

16. The JCMT BISTRO Survey:The Magnetic Field of the Barnard 1 Star-forming Region

Author: Coude, S, Bastien, P, Houde, M, Sadavoy, S, Friesen, R, Di Francesco, J, Johnstone, D, Mairs, S, Hasegawa, T, Kwon, W, Lai, S-P, Qiu, K, Ward-Thompson, D, Berry, D, Chen, MC-Y, Fiege, J, Franzmann, E, Hatchell, J, Lacaille, K, Matthews, BC, Moriarty-Schieven, GH, Pon, A, Andre, P, Arzoumanian, D, Aso, Y, Byun, D-Y, Eswaraiah, C, Chen, H-R, Chen, WP, Ching, T-C, Cho, J, Choi, M, Chrysostomou, A, Chung, EJ, Doi, Y, Drabek-Maunder, E, Dowell, CD, Eyres, SPS, Falle, S, Friberg, P, Fuller, G, Furuya, RS, Gledhill, T, Graves, SF, Greaves, JS, Griffin, MJ, Gu, Q, Hayashi, SS, Hoang, T, Holland, W, Inoue, T, Inutsuka, S-I, Iwasaki, K, Jeong, I-G, Kanamori, Y, Kataoka, A, Kang, J-H, Kang, M, Kang, S-J, Kawabata, KS, Kemper, F, Kim, G, Kim, J, Kim, K-T, Kim, KH, Kim, M-R, Kim, S, Kirk, JM, Kobayashi, MIN, Koch, PM, Kwon, J, Lee, J-E, Lee, CW, Lee, S-S, Li, D, Li, H-B, Liu, H-L, Liu, J, Liu, S-Y, Liu, T, van Loo, S, Lyo, A-R, Matsumura, M, Nagata, T, Nakamura, F, Nakanishi, H, Ohashi, N, Onaka, T, Parsons, H, Pattle, K, Peretto, N, Pyo, T-S, Qian, L, Rao, R, Rawlings, MG, Retter, B, Richer, J, Rigby, A, Robitaille, J-F, Saito, H, Savini, G, Scaife, AMM, Seta, M, Shinnaga, H, Soam, A, Tamura, M, Tang, Y-W, Tomisaka, K, Tsukamoto, Y, Wang, H, Wang, J-W, Whitworth, AP, Yen, H-W, Yoo, H, Yuan, J, Zenko, T, Zhang, C-P, Zhang, G, Zhou, J, Zhu, L, and The BISTRO Collaboration
Subjects: 010504 meteorology & atmospheric sciences, INFRARED POLARIMETRY, RADIATIVE TORQUES, FOS: Physical sciences, Astrophysics, F500, Astrophysics::Cosmology and Extragalactic Astrophysics, Lambda, 01 natural sciences, ISM: clouds, MOLECULAR, 0103 physical sciences, POLARIZATION MEASUREMENTS, SCUBA-2, GOULD BELT SURVEY, ISM: individual objects (Barnard 1), individual objects (Barnard 1) [ISM], ISM [submillimeter], 010303 astronomy & astrophysics, James Clerk Maxwell Telescope, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, LINEAR-POLARIZATION, polarization, stars: formation, formation [stars], Magnetic energy, Linear polarization, Molecular cloud, F510, CLOUDS, magnetic fields [ISM], Astronomy and Astrophysics, Polarization (waves), Astrophysics - Astrophysics of Galaxies, H2O MASERS, Magnetic field, ALIGNMENT, Amplitude, Physics and Astronomy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), submillimeter: ISM, ISM: magnetic fields, INTERSTELLAR GRAINS, clouds [ISM]
Abstract: 著者人数: The B-fields In STar-forming Regions Observations (BISTRO) Collaboration 121名 (所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 權, 靜美), Number of authors: The B-fields In STar-forming Regions Observations (BISTRO) Collaboration 121 (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS): Kwon, Jungmi), Accepted: 2019-04-18, 資料番号: SA1190042000
Published: 2019

17. First Results From BISTRO - A Scuba-2 Polarimeter Survey Of The Gould Belt

Author: Ward-Thompson, D, Pattle, K, Bastien, P, Furuya, RS, Kwon, W, Lai, S-P, Qiu, K, Berry, D, Choi, M, Coude, S, Di Fransesco, J, Hoang, T, Franzmann, E, Friberg, P, Graves, S, Houde, M, Johnstone, D, Kirk, JM, Koch, PM, Kwon, J, Won Lee, C, Li, D, Matthews, BC, Mottram, JC, Parsons, H, Pon, A, Rao, R, Rawlings, M, Shinnaga, H, Sadavoy, S, Van Loo, S, Aso, Y, Byun, D-Y, Chakali, E, Chen, H-R, Chen, MC-Y, Chen, WP, Ching, T-C, Cho, J, Chrysostomou, A, Chung, EJ, Doi, Y, Drabek-Maunder, E, Eyres, SPS, Fiege, J, Friesen, RK, Fuller, G, Gledhill, T, Griffin, MJ, Gu, Q, Hasegawa, T, Hatchell, J, Hayashi, SS, Holland, W, Inoue, T, Inutsuka, S-I, Iwasaki, K, Jeong, I-G, Kang, J-H, Kang, M, Kang, S-J, Kawabata, KS, Kemper, F, Kim, G, Kim, J, Kim, K-T, Kim, KH, Kim, M-R, Kim, S, Lacaille, KM, Lee, J-E, Lee, S-S, Li, H-B, Liu, H-L, Liu, J, Liu, S-Y, Liu, T, Lyo, A-R, Mairs, S, Matsumura, M, Moriarty-Schieven, GH, Nakamura, F, Nakanishi, H, Ohashi, N, Onaka, T, Peretto, N, Pyo, T-S, Qian, L, Retter, B, Richer, J, Rigby, A, Robitaille, J-F, Savini, G, Scaife, AMM, Soam, A, Tamura, M, Tang, Y-W, Tomisaka, K, Wang, H, Wang, J-W, Withworth, AP, Yen, H-W, Yoo, H, Yuan, J, Zhang, C-P, Zhang, G, Zhou, J, Zhu, L, Andre, P, Dowell, CD, Falle, SAEG, and Tsukamoto, Y
Abstract: We present the rst results from the B- elds In STar-forming Region Observations (BISTRO) survey, using the Sub-millimetre Common-User Bolometer Array 2 (SCUBA-2) camera, with its associated polarimeter (POL-2), on the James Clerk Maxwell Telescope (JCMT) in Hawaii. We discuss the survey's aims and objectives. We describe the rationale behind the survey, and the questions which the survey will aim to answer. The most important of these is the role of magnetic fields in the star formation process on the scale of individual filaments and cores in dense regions. We describe the data acquisition and reduction processes for POL-2, demonstrating both repeatability and consistency with previous data. We present a first-look analysis of the rst results from the BISTRO survey in the OMC 1 region. We see that the magnetic field lies approximately perpendicular to the famous `integral filament' in the densest regions of that filament. Furthermore, we see an `hour-glass' magnetic field morphology extending beyond the densest region of the integral filament into the less-dense surrounding material, and discuss possible causes for this. We also discuss the more complex morphology seen along the Orion Bar region. We examine the morphology of the field along the lower-density north-eastern filament. We find consistency with previous theoretical models that predict magnetic fields lying parallel to low-density, non-self-gravitating filaments, and perpendicular to higher-density, self-gravitating filaments.
Published: 2017

18. The JCMT Gould Belt Survey: A First Look at the Auriga–California Molecular Cloud with SCUBA-2

Author: Broekhoven-Fiene, H., primary, Matthews, B. C., additional, Harvey, P., additional, Kirk, H., additional, Chen, M., additional, Currie, M. J., additional, Pattle, K., additional, Lane, J., additional, Buckle, J., additional, Francesco, J. Di, additional, Drabek-Maunder, E., additional, Johnstone, D., additional, Berry, D. S., additional, Fich, M., additional, Hatchell, J., additional, Jenness, T., additional, Mottram, J. C., additional, Nutter, D., additional, Pineda, J. E., additional, Quinn, C., additional, Salji, C., additional, Tisi, S., additional, Hogerheijde, M. R., additional, Ward-Thompson, D., additional, Bastien, P., additional, Bresnahan, D., additional, Butner, H., additional, Chrysostomou, A., additional, Coude, S., additional, Davis, C. J., additional, Duarte-Cabral, A., additional, Fiege, J., additional, Friberg, P., additional, Friesen, R., additional, Fuller, G. A., additional, Graves, S., additional, Greaves, J., additional, Gregson, J., additional, Holland, W., additional, Joncas, G., additional, Kirk, J. M., additional, Knee, L. B. G., additional, Mairs, S., additional, Marsh, K., additional, Moriarty-Schieven, G., additional, Mowat, C., additional, Rawlings, J., additional, Richer, J., additional, Robertson, D., additional, Rosolowsky, E., additional, Rumble, D., additional, Sadavoy, S., additional, Thomas, H., additional, Tothill, N., additional, Viti, S., additional, White, G. J., additional, Wilson, C. D., additional, Wouterloot, J., additional, Yates, J., additional, and Zhu, M., additional
Published: 2018
Full Text: View/download PDF

19. The JCMT Gould Belt Survey: first results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population

Author: Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Francesco, J. Di, Hogerheijde, M. R., André, Ph, Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., Zhu, M., Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Francesco, J. Di, Hogerheijde, M. R., André, Ph, Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: In this paper, we present the first observations of the Ophiuchus molecular cloud performed as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) with the SCUBA-2 instrument. We demonstrate methods for combining these data with previous HARP CO, Herschel, and IRAM N2H+ observations in order to accurately quantify the properties of the SCUBA-2 sources in Ophiuchus. We produce a catalogue of all of the sources found by SCUBA-2. We separate these into protostars and starless cores. We list all of the starless cores and perform a full virial analysis, including external pressure. This is the first time that external pressure has been included in this level of detail. We find that the majority of our cores are either bound or virialized. Gravitational energy and external pressure are on average of a similar order of magnitude, but with some variation from region to region. We find that cores in the Oph A region are gravitationally bound prestellar cores, while cores in the Oph C and E regions are pressure-confined. We determine that N2H+ is a good tracer of the bound material of prestellar cores, although we find some evidence for N2H+ freeze-out at the very highest core densities. We find that non-thermal linewidths decrease substantially between the gas traced by C18O and that traced by N2H+, indicating the dissipation of turbulence at higher densities. We find that the critical Bonnor-Ebert stability criterion is not a good indicator of the boundedness of our cores. We detect the pre-brown dwarf candidate Oph B-11 and find a flux density and mass consistent with previous work. We discuss regional variations in the nature of the cores and find further support for our previous hypothesis of a global evolutionary gradient across the cloud from south-west to north-east, indicating sequential star formation across the region
Published: 2017

20. The JCMT Gould Belt Survey: a first look at dense cores in Orion B

Author: Kirk, H., Francesco, J. Di, Johnstone, D., Duarte-Cabral, A., Sadavoy, S., Hatchell, J., Mottram, J. C., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, Derek, Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, Jason Matthew, Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., Zhu, M., Kirk, H., Francesco, J. Di, Johnstone, D., Duarte-Cabral, A., Sadavoy, S., Hatchell, J., Mottram, J. C., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, Derek, Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, Jason Matthew, Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We present a first look at the SCUBA-2 observations of three sub-regions of the Orion B molecular cloud: LDN 1622, NGC 2023/2024, and NGC 2068/2071, from the JCMT Gould Belt Legacy Survey. We identify 29, 564, and 322 dense cores in L1622, NGC 2023/2024, and NGC 2068/2071 respectively, using the SCUBA-2 850 μm map, and present their basic properties, including their peak fluxes, total fluxes, and sizes, and an estimate of the corresponding 450 μm peak fluxes and total fluxes, using the FellWalker source extraction algorithm. Assuming a constant temperature of 20 K, the starless dense cores have a mass function similar to that found in previous dense core analyses, with a Salpeter-like slope at the high-mass end. The majority of cores appear stable to gravitational collapse when considering only thermal pressure; indeed, most of the cores which have masses above the thermal Jeans mass are already associated with at least one protostar. At higher cloud column densities, above 1–2 × 1023 cm−2, most of the mass is found within dense cores, while at lower cloud column densities, below 1 × 1023 cm−2, this fraction drops to 10% or lower. Overall, the fraction of dense cores associated with a protostar is quite small (<8%), but becomes larger for the densest and most centrally concentrated cores. NGC 2023/2024 and NGC 2068/2071 appear to be on the path to forming a significant number of stars in the future, while L1622 has little additional mass in dense cores to form many new stars.
Published: 2016

21. THE JCMT GOULD BELT SURVEY: EVIDENCE FOR DUST GRAIN EVOLUTION IN PERSEUS STAR-FORMING CLUMPS

Author: Chen, Michael Chun-Yuan, primary, Francesco, J. Di, additional, Johnstone, D., additional, Sadavoy, S., additional, Hatchell, J., additional, Mottram, J. C., additional, Kirk, H., additional, Buckle, J., additional, Berry, D. S., additional, Broekhoven-Fiene, H., additional, Currie, M. J., additional, Fich, M., additional, Jenness, T., additional, Nutter, D., additional, Pattle, K., additional, Pineda, J. E., additional, Quinn, C., additional, Salji, C., additional, Tisi, S., additional, Hogerheijde, M. R., additional, Ward-Thompson, D., additional, Bastien, P., additional, Bresnahan, D., additional, Butner, H., additional, Chrysostomou, A., additional, Coude, S., additional, Davis, C. J., additional, Drabek-Maunder, E., additional, Duarte-Cabral, A., additional, Fiege, J., additional, Friberg, P., additional, Friesen, R., additional, Fuller, G. A., additional, Graves, S., additional, Greaves, J., additional, Gregson, J., additional, Holland, W., additional, Joncas, G., additional, Kirk, J. M., additional, Knee, L. B. G., additional, Mairs, S., additional, Marsh, K., additional, Matthews, B. C., additional, Moriarty-Schieven, G., additional, Mowat, C., additional, Pezzuto, S., additional, Rawlings, J., additional, Richer, J., additional, Robertson, D., additional, Rosolowsky, E., additional, Rumble, D., additional, Schneider-Bontemps, N., additional, Thomas, H., additional, Tothill, N., additional, Viti, S., additional, White, G. J., additional, Wouterloot, J., additional, Yates, J., additional, and Zhu, M., additional
Published: 2016
Full Text: View/download PDF

22. The JCMT Gould Belt Survey: evidence for radiative heating and contamination in the W40 complex

Author: Rumble, D., primary, Hatchell, J., additional, Pattle, K., additional, Kirk, H., additional, Wilson, T., additional, Buckle, J., additional, Berry, D.S., additional, Broekhoven-Fiene, H., additional, Currie, M.J., additional, Fich, M., additional, Jenness, T., additional, Johnstone, D., additional, Mottram, J. C., additional, Nutter, D., additional, Pineda, J.E., additional, Quinn, C., additional, Salji, C., additional, Tisi, S., additional, Walker-Smith, S., additional, Francesco, J. Di, additional, Hogerheijde, M.R., additional, Ward-Thompson, D., additional, Bastien, P., additional, Bresnahan, D., additional, Butner, H., additional, Chen, M., additional, Chrysostomou, A., additional, Coude, S., additional, Davis, C.J., additional, Drabek-Maunder, E., additional, Duarte-Cabral, A., additional, Fiege, J., additional, Friberg, P., additional, Friesen, R., additional, Fuller, G.A., additional, Graves, S., additional, Greaves, J., additional, Gregson, J., additional, Holland, W., additional, Joncas, G., additional, Kirk, J. M., additional, Knee, L. B. G., additional, Mairs, S., additional, Marsh, K., additional, Matthews, B. C., additional, Moriarty-Schieven, G., additional, Mowat, C., additional, Rawlings, J., additional, Richer, J., additional, Robertson, D., additional, Rosolowsky, E., additional, Sadavoy, S., additional, Thomas, H., additional, Tothill, N., additional, Viti, S., additional, White, G. J., additional, Wouterloot, J., additional, Yates, J., additional, and Zhu, M., additional
Published: 2016
Full Text: View/download PDF

23. THE JCMT GOULD BELT SURVEY: A FIRST LOOK AT DENSE CORES IN ORION B

Author: Kirk, H., primary, Francesco, J. Di, additional, Johnstone, D., additional, Duarte-Cabral, A., additional, Sadavoy, S., additional, Hatchell, J., additional, Mottram, J. C., additional, Buckle, J., additional, Berry, D. S., additional, Broekhoven-Fiene, H., additional, Currie, M. J., additional, Fich, M., additional, Jenness, T., additional, Nutter, D., additional, Pattle, K., additional, Pineda, J. E., additional, Quinn, C., additional, Salji, C., additional, Tisi, S., additional, Hogerheijde, M. R., additional, Ward-Thompson, D., additional, Bastien, P., additional, Bresnahan, D., additional, Butner, H., additional, Chen, M., additional, Chrysostomou, A., additional, Coude, S., additional, Davis, C. J., additional, Drabek-Maunder, E., additional, Fiege, J., additional, Friberg, P., additional, Friesen, R., additional, Fuller, G. A., additional, Graves, S., additional, Greaves, J., additional, Gregson, J., additional, Holland, W., additional, Joncas, G., additional, Kirk, J. M., additional, Knee, L. B. G., additional, Mairs, S., additional, Marsh, K., additional, Matthews, B. C., additional, Moriarty-Schieven, G., additional, Mowat, C., additional, Rawlings, J., additional, Richer, J., additional, Robertson, D., additional, Rosolowsky, E., additional, Rumble, D., additional, Thomas, H., additional, Tothill, N., additional, Viti, S., additional, White, G. J., additional, Wouterloot, J., additional, Yates, J., additional, and Zhu, M., additional
Published: 2016
Full Text: View/download PDF

24. The JCMT Gould Belt Survey: constraints on prestellar core properties in Orion A North

Author: Salji, C. J., Richer, J. S., Buckle, J. V., Hatchell, J., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Tisi, S., Walker-Smith, S., Francesco, J. D., Hogerheijde, M. R., Ward-Thompson, Derek, Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, Jason Matthew, Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., Zhu, M., Salji, C. J., Richer, J. S., Buckle, J. V., Hatchell, J., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Tisi, S., Walker-Smith, S., Francesco, J. D., Hogerheijde, M. R., Ward-Thompson, Derek, Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, Jason Matthew, Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We employ SCUBA-2 (Submillimetre Common-User Bolometer Array 2) observations of the Orion A North molecular cloud to derive column density and temperature maps. We apply a novel, Hessian-based structural identification algorithm for detection of prestellar cores to these data, allowing for automated generation of the prestellar mass function. The resulting mass function is observed to peak at 1.39+0.18−0.19 M⊙, indicating a star-forming efficiency lower limit of ∼14 per cent when compared with the Orion nebula Cluster initial mass function (IMF) peak. Additionally, the prestellar mass function is observed to decay with a high-mass power-law exponent α=2.53+0.16−0.14, indicating approximate functional similarity with the Salpeter IMF (α = 2.35). This result, when combined with the results of previous investigations suggests a regional dependence of the star-forming efficiency.
Published: 2015

25. The JCMT Gould Belt Survey: SCUBA-2 observations of circumstellar disks in L 1495

Author: Buckle, J.V., Drabek-Maunder, E., Greaves, J., Richer, J.S., Matthews, B.C., Johnstone, D., Kirk, H., Beaulieu, S.F., Berry, D.S., Broekhoven-Fiene, H., Currie, M.J., Fich, M., Hatchell, J., Jenness, T., Mottram, J.C., Nutter, D., Pattle, K., Pineda, J.E., Salji, C., Tisi, S., Di Francesco, J., Hogerheijde, M.R., Ward-Thompson, Derek, Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C.J., Duarte-Cabral, A., Friberg, P., Friesen, R., Fuller, G.A., Graves, S., Gregson, J., Holland, W., Joncas, G., Kirk, Jason Matthew, Knee, L.B.G., Mairs, S., Marsh, K., Moriarty-Schieven, G., Rawlings, J., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G.J., Wilson, C.D., Wouterloot, J., Yates, J., Zhu, M., Buckle, J.V., Drabek-Maunder, E., Greaves, J., Richer, J.S., Matthews, B.C., Johnstone, D., Kirk, H., Beaulieu, S.F., Berry, D.S., Broekhoven-Fiene, H., Currie, M.J., Fich, M., Hatchell, J., Jenness, T., Mottram, J.C., Nutter, D., Pattle, K., Pineda, J.E., Salji, C., Tisi, S., Di Francesco, J., Hogerheijde, M.R., Ward-Thompson, Derek, Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C.J., Duarte-Cabral, A., Friberg, P., Friesen, R., Fuller, G.A., Graves, S., Gregson, J., Holland, W., Joncas, G., Kirk, Jason Matthew, Knee, L.B.G., Mairs, S., Marsh, K., Moriarty-Schieven, G., Rawlings, J., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G.J., Wilson, C.D., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We present 850$\mu$m and 450$\mu$m data from the JCMT Gould Belt Survey obtained with SCUBA-2 and characterise the dust attributes of Class I, Class II and Class III disk sources in L1495. We detect 23% of the sample at both wavelengths, with the detection rate decreasing through the Classes from I--III. The median disk mask is 1.6$\times 10^{-3}$M$_{\odot}$, and only 7% of Class II sources have disk masses larger than 20 Jupiter masses. We detect a higher proportion of disks towards sources with stellar hosts of spectral type K than spectral type M. Class II disks with single stellar hosts of spectral type K have higher masses than those of spectral type M, supporting the hypothesis that higher mass stars have more massive disks. Variations in disk masses calculated at the two wavelengths suggests there may be differences in dust opacity and/or dust temperature between disks with hosts of spectral types K to those with spectral type M.
Published: 2015

26. The JCMT Gould Belt Survey: first results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population

Author: Pattle, Katherine M, Ward-Thompson, Derek, Kirk, Jason Matthew, White, G. J, Drabek-Maunder, E, Buckle, J, Beaulieu, S. F, Berry, D. S, Broekhoven-Fiene, H, Currie, M. J, Fich, M, Hatchell, J, Kirk, H, Jenness, T, Johnstone, D, Mottram, J.C, Nutter, D, Pineda, J.E, Quinn, C, Salji, C, Tisi, S, Walker-Smith, S, Di Francesco, J, Hogerheijde, M.R, André, PH, Bastien, P, Bresnahan, D, Butner, H, Chen, M, Chrysostomou, A, Coude, S, Davis, C. J, Duarte-Cabral, A, Fiege, J, Friberg, P, Friesen, R, Fuller, G. A, Graves, S, Gregson, J, Griffin, M. J, Holland, W, Joncas, G, Knee, L. B. G, Könyves, V, Mairs, S, Marsh, K, Matthews, B. C, Moriarty-Schieven, G, Rawlings, J, Richer, J, Robertson, D, Rosolowsky, E, Rumble, D, Sadavoy, S, Spinoglio, L, Thomas, H, Tothill, N, Viti, S, Wouterloot, J, Yates, J, Zhu, M, Pattle, Katherine M, Ward-Thompson, Derek, Kirk, Jason Matthew, White, G. J, Drabek-Maunder, E, Buckle, J, Beaulieu, S. F, Berry, D. S, Broekhoven-Fiene, H, Currie, M. J, Fich, M, Hatchell, J, Kirk, H, Jenness, T, Johnstone, D, Mottram, J.C, Nutter, D, Pineda, J.E, Quinn, C, Salji, C, Tisi, S, Walker-Smith, S, Di Francesco, J, Hogerheijde, M.R, André, PH, Bastien, P, Bresnahan, D, Butner, H, Chen, M, Chrysostomou, A, Coude, S, Davis, C. J, Duarte-Cabral, A, Fiege, J, Friberg, P, Friesen, R, Fuller, G. A, Graves, S, Gregson, J, Griffin, M. J, Holland, W, Joncas, G, Knee, L. B. G, Könyves, V, Mairs, S, Marsh, K, Matthews, B. C, Moriarty-Schieven, G, Rawlings, J, Richer, J, Robertson, D, Rosolowsky, E, Rumble, D, Sadavoy, S, Spinoglio, L, Thomas, H, Tothill, N, Viti, S, Wouterloot, J, Yates, J, and Zhu, M
Abstract: In this paper, we present the first observations of the Ophiuchus molecular cloud performed as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) with the SCUBA-2 instrument.We demonstratemethods for combining these datawith previous HARP CO, Herschel, and IRAM N2H+ observations in order to accurately quantify the properties of the SCUBA-2 sources in Ophiuchus. We produce a catalogue of all of the sources found by SCUBA-2. We separate these into protostars and starless cores. We list all of the starless cores and perform a full virial analysis, including external pressure. This is the first time that external pressure has been included in this level of detail. We find that the majority of our cores are either bound or virialized. Gravitational energy and external pressure are on average of a similar order of magnitude, but with some variation from region to region. We find that cores in the Oph A region are gravitationally bound prestellar cores, while cores in the Oph C and E regions are pressure-confined. We determine that N2H+ is a good tracer of the bound material of prestellar cores, although we find some evidence for N2H+ freeze-out at the very highest core densities.We find that non-thermal linewidths decrease substantially between the gas traced by C18O and that traced by N2H+, indicating the dissipation of turbulence at higher densities. We find that the critical Bonnor–Ebert stability criterion is not a good indicator of the boundedness of our cores. We detect the pre-brown dwarf candidate Oph B-11 and find a flux density and mass consistent with previous work. We discuss regional variations in the nature of the cores and find further support for our previous hypothesis of a global evolutionary gradient across the cloud from south-west to north-east, indicating sequential star formation across the region.
Published: 2015

27. The JCMT Gould Belt Survey: first results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population

Author: Pattle, K., primary, Ward-Thompson, D., additional, Kirk, J. M., additional, White, G. J., additional, Drabek-Maunder, E., additional, Buckle, J., additional, Beaulieu, S. F., additional, Berry, D. S., additional, Broekhoven-Fiene, H., additional, Currie, M. J., additional, Fich, M., additional, Hatchell, J., additional, Kirk, H., additional, Jenness, T., additional, Johnstone, D., additional, Mottram, J. C., additional, Nutter, D., additional, Pineda, J. E., additional, Quinn, C., additional, Salji, C., additional, Tisi, S., additional, Walker-Smith, S., additional, Francesco, J. Di, additional, Hogerheijde, M. R., additional, André, Ph., additional, Bastien, P., additional, Bresnahan, D., additional, Butner, H., additional, Chen, M., additional, Chrysostomou, A., additional, Coude, S., additional, Davis, C. J., additional, Duarte-Cabral, A., additional, Fiege, J., additional, Friberg, P., additional, Friesen, R., additional, Fuller, G. A., additional, Graves, S., additional, Greaves, J., additional, Gregson, J., additional, Griffin, M. J., additional, Holland, W., additional, Joncas, G., additional, Knee, L. B. G., additional, Könyves, V., additional, Mairs, S., additional, Marsh, K., additional, Matthews, B. C., additional, Moriarty-Schieven, G., additional, Rawlings, J., additional, Richer, J., additional, Robertson, D., additional, Rosolowsky, E., additional, Rumble, D., additional, Sadavoy, S., additional, Spinoglio, L., additional, Thomas, H., additional, Tothill, N., additional, Viti, S., additional, Wouterloot, J., additional, Yates, J., additional, and Zhu, M., additional
Published: 2015
Full Text: View/download PDF

28. The JCMT Gould Belt Survey: SCUBA-2 observations of circumstellar discs in L 1495

Author: Buckle, J. V., primary, Drabek-Maunder, E., additional, Greaves, J., additional, Richer, J. S., additional, Matthews, B.C., additional, Johnstone, D., additional, Kirk, H., additional, Beaulieu, S. F., additional, Berry, D. S., additional, Broekhoven-Fiene, H., additional, Currie, M. J., additional, Fich, M., additional, Hatchell, J., additional, Jenness, T., additional, Mottram, J. C., additional, Nutter, D., additional, Pattle, K., additional, Pineda, J. E., additional, Salji, C., additional, Tisi, S., additional, Francesco, J. Di, additional, Hogerheijde, M. R., additional, Ward-Thompson, D., additional, Bastien, P., additional, Butner, H., additional, Chen, M., additional, Chrysostomou, A., additional, Coude, S., additional, Davis, C. J., additional, Duarte-Cabral, A., additional, Friberg, P., additional, Friesen, R., additional, Fuller, G. A., additional, Graves, S., additional, Gregson, J., additional, Holland, W., additional, Joncas, G., additional, Kirk, J. M., additional, Knee, L. B. G., additional, Mairs, S., additional, Marsh, K., additional, Moriarty-Schieven, G., additional, Rawlings, J., additional, Rosolowsky, E., additional, Rumble, D., additional, Sadavoy, S., additional, Thomas, H., additional, Tothill, N., additional, Viti, S., additional, White, G. J., additional, Wilson, C. D., additional, Wouterloot, J., additional, Yates, J., additional, and Zhu, M., additional
Published: 2015
Full Text: View/download PDF

29. The JCMT Gould Belt Survey: constraints on prestellar core properties in Orion A North

Author: Salji, C. J., primary, Richer, J. S., additional, Buckle, J. V., additional, Hatchell, J., additional, Kirk, H., additional, Beaulieu, S. F., additional, Berry, D. S., additional, Broekhoven-Fiene, H., additional, Currie, M. J., additional, Fich, M., additional, Jenness, T., additional, Johnstone, D., additional, Mottram, J. C., additional, Nutter, D., additional, Pattle, K., additional, Pineda, J. E., additional, Quinn, C., additional, Tisi, S., additional, Walker-Smith, S., additional, Francesco, J. Di, additional, Hogerheijde, M. R., additional, Ward-Thompson, D., additional, Bastien, P., additional, Butner, H., additional, Chen, M., additional, Chrysostomou, A., additional, Coude, S., additional, Davis, C. J., additional, Drabek-Maunder, E., additional, Duarte-Cabral, A., additional, Fiege, J., additional, Friberg, P., additional, Friesen, R., additional, Fuller, G. A., additional, Graves, S., additional, Greaves, J., additional, Gregson, J., additional, Holland, W., additional, Joncas, G., additional, Kirk, J. M., additional, Knee, L. B. G., additional, Mairs, S., additional, Marsh, K., additional, Matthews, B. C., additional, Moriarty-Schieven, G., additional, Rawlings, J., additional, Robertson, D., additional, Rosolowsky, E., additional, Rumble, D., additional, Sadavoy, S., additional, Thomas, H., additional, Tothill, N., additional, Viti, S., additional, White, G. J., additional, Wilson, C. D., additional, Wouterloot, J., additional, Yates, J., additional, and Zhu, M., additional
Published: 2015
Full Text: View/download PDF

30. The JCMT Gould Belt Survey: evidence for radiative heating in Serpens MWC 297 and its influence on local star formation

Author: Rumble, D., primary, Hatchell, J., additional, Gutermuth, R. A., additional, Kirk, H., additional, Buckle, J., additional, Beaulieu, S. F., additional, Berry, D. S., additional, Broekhoven-Fiene, H., additional, Currie, M. J., additional, Fich, M., additional, Jenness, T., additional, Johnstone, D., additional, Mottram, J. C., additional, Nutter, D., additional, Pattle, K., additional, Pineda, J. E., additional, Quinn, C., additional, Salji, C., additional, Tisi, S., additional, Walker-Smith, S., additional, Francesco, J. Di, additional, Hogerheijde, M. R., additional, Ward-Thompson, D., additional, Allen, L. E., additional, Cieza, L. A., additional, Dunham, M. M., additional, Harvey, P. M., additional, Stapelfeldt, K. R., additional, Bastien, P., additional, Butner, H., additional, Chen, M., additional, Chrysostomou, A., additional, Coude, S., additional, Davis, C. J., additional, Drabek-Maunder, E., additional, Duarte-Cabral, A., additional, Fiege, J., additional, Friberg, P., additional, Friesen, R., additional, Fuller, G. A., additional, Graves, S., additional, Greaves, J., additional, Gregson, J., additional, Holland, W., additional, Joncas, G., additional, Kirk, J. M., additional, Knee, L. B. G., additional, Mairs, S., additional, Marsh, K., additional, Matthews, B. C., additional, Moriarty-Schieven, G., additional, Rawlings, J., additional, Richer, J., additional, Robertson, D., additional, Rosolowsky, E., additional, Sadavoy, S., additional, Thomas, H., additional, Tothill, N., additional, Viti, S., additional, White, G. J., additional, Wilson, C. D., additional, Wouterloot, J., additional, Yates, J., additional, and Zhu, M., additional
Published: 2015
Full Text: View/download PDF

31. Icephobic PTFE coatings for wind turbines operating in cold climate conditions.

Author: Karmouch, R., Coude, S., Abel, G., and Ross, G.G.
Published: 2009
Full Text: View/download PDF

32. VizieR Online Data Catalog: JCMT Gould Belt Survey: dense cores in Orion B (Kirk+, 2016)

Author: Kirk, H., Di Francesco, J., Doug Johnstone, Duarte-Cabral, A., Sadavoy, S., Hatchell, J., Mottram, J. C., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.

33. VizieR Online Data Catalog: JCMT Gould Belt Survey: Serpens MWC 297 (Rumble+, 2015)

Author: Rumble, D., Hatchell, J., Gutermuth, R. A., Kirk, H., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di, Francesco J., Hogerheijde, M. R., Ward-Thompson, D., Allen, L. E., Cieza, L. A., Dunham, M. M., Harvey, P. M., Stapelfeldt, K. R., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Sadavoy, S., Holly Thomas, Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.

34. VizieR Online Data Catalog: JCMT Gould Belt Survey: W40 complex (Rumble+, 2016)

Author: Rumble, D., Hatchell, J., Pattle, K., Kirk, H., Wilson, T., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Doug Johnstone, Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di, Francesco J., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.

35. The JCMT Gould Belt Survey: A First Look at the Auriga–California Molecular Cloud with SCUBA-2

Author: Broekhoven-Fiene, H., Matthews, B. C., Harvey, P., Kirk, H., Chen, M., Currie, M. J., Pattle, K., Lane, J., Buckle, J., Francesco, J. Di, Drabek-Maunder, E., Johnstone, D., Berry, D. S., Fich, M., Hatchell, J., Jenness, T., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., Zhu, M., Broekhoven-Fiene, H., Matthews, B. C., Harvey, P., Kirk, H., Chen, M., Currie, M. J., Pattle, K., Lane, J., Buckle, J., Francesco, J. Di, Drabek-Maunder, E., Johnstone, D., Berry, D. S., Fich, M., Hatchell, J., Jenness, T., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We present 850 and 450 μm observations of the dense regions within the Auriga–California molecular cloud using SCUBA-2 as part of the JCMT Gould Belt Legacy Survey to identify candidate protostellar objects, measure the masses of their circumstellar material (disk and envelope), and compare the star formation to that in the Orion A molecular cloud. We identify 59 candidate protostars based on the presence of compact submillimeter emission, complementing these observations with existing Herschel/SPIRE maps. Of our candidate protostars, 24 are associated with young stellar objects (YSOs) in the Spitzer and Herschel/PACS catalogs of 166 and 60 YSOs, respectively (177 unique), confirming their protostellar nature. The remaining 35 candidate protostars are in regions, particularly around LkHα 101, where the background cloud emission is too bright to verify or rule out the presence of the compact 70 μm emission that is expected for a protostellar source. We keep these candidate protostars in our sample but note that they may indeed be prestellar in nature. Our observations are sensitive to the high end of the mass distribution in Auriga–Cal. We find that the disparity between the richness of infrared star-forming objects in Orion A and the sparsity in Auriga–Cal extends to the submillimeter, suggesting that the relative star formation rates have not varied over the Class II lifetime and that Auriga–Cal will maintain a lower star formation efficiency.

36. The JCMT Gould Belt Survey: evidence for radiative heating in Serpens MWC 297 and its influence on local star formation

Author: Rumble, D., Hatchell, J., Gutermuth, R. A., Kirk, H., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Francesco, J. D., Hogerheijde, M. R., Ward-Thompson, D., Allen, L. E., Cieza, L. A., Dunham, M. M., Harvey, P. M., Stapelfeldt, K. R., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., Zhu, M., Rumble, D., Hatchell, J., Gutermuth, R. A., Kirk, H., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Francesco, J. D., Hogerheijde, M. R., Ward-Thompson, D., Allen, L. E., Cieza, L. A., Dunham, M. M., Harvey, P. M., Stapelfeldt, K. R., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We present SCUBA-2 450 and 850 μm observations of the Serpens MWC 297 region, part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey of nearby star-forming regions. Simulations suggest that radiative feedback influences the star formation process and we investigate observational evidence for this by constructing temperature maps. Maps are derived from the ratio of SCUBA-2 fluxes and a two-component model of the JCMT beam for a fixed dust opacity spectral index of β = 1.8. Within 40 arcsec of the B1.5Ve Herbig star MWC 297, the submillimetre fluxes are contaminated by free-free emission with a spectral index of 1.03 ± 0.02, consistent with an ultracompact H II region and polar winds/jets. Contamination accounts for 73 ± 5 per cent and 82 ± 4 per cent of peak flux at 450 μm and 850 μm, respectively. The residual thermal disc of the star is almost undetectable at these wavelengths. Young stellar objects (YSOs) are confirmed where SCUBA-2 850 μm clumps identified by the FELLWALKER algorithm coincide with Spitzer Gould Belt Survey detections. We identify 23 objects and use Tbol to classify nine YSOs with masses 0.09 to 5.1 M⊙. We find two Class 0, one Class 0/I, three Class I and three Class II sources. The mean temperature is 15 ± 2 K for the nine YSOs and 32 ± 4 K for the 14 starless clumps. We observe a starless clump with an abnormally high mean temperature of 46 ± 2 K and conclude that it is radiatively heated by the star MWC 297. Jeans stability provides evidence that radiative heating by the star MWC 297 may be suppressing clump collapse.

37. The JCMT Gould Belt Survey: evidence for radiative heating and contamination in the W40 complex

Author: Rumble, D., Hatchell, J., Pattle, K., Kirk, H., Wilson, T., Buckle, J., Berry, D.S., Broekhoven-Fiene, H., Currie, M.J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J.E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M.R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C.J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G.A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., Zhu, M., Rumble, D., Hatchell, J., Pattle, K., Kirk, H., Wilson, T., Buckle, J., Berry, D.S., Broekhoven-Fiene, H., Currie, M.J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J.E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M.R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C.J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G.A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We present SCUBA-2 450 μm and 850 μm observations of the W40 complex in the Serpens-Aquila region as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) of nearby star-forming regions. We investigate radiative heating by constructing temperature maps from the ratio of SCUBA-2 fluxes using a fixed dust opacity spectral index, β = 1.8, and a beam convolution kernel to achieve a common 14.8 arcsec resolution. We identify 82 clumps ranging between 10 and 36 K with a mean temperature of 20 ± 3 K. Clump temperature is strongly correlated with proximity to the external OB association and there is no evidence that the embedded protostars significantly heat the dust. We identify 31 clumps that have cores with densities greater than 105cm-3. 13 of these cores contain embedded Class 0/I protostars. Many cores are associated with bright-rimmed clouds seen in Herschel 70 μm images. From JCMT HARP observations of the 12CO 3-2 line, we find contamination of the 850 μm band of up to 20 per cent. We investigate the free-free contribution to SCUBA-2 bands from large-scale and ultracompact HII regions using archival VLA data and find the contribution is limited to individual stars, accounting for 9 per cent of flux per beam at 450 μm or 12 per cent at 850 μm in these cases. We conclude that radiative heating has potentially influenced the formation of stars in the Dust Arc sub-region, favouring Jeans stable clouds in the warm east and fragmentation in the cool west.

38. The JCMT Gould Belt Survey: evidence for dust grain evolution in Perseus star-forming clumps

Author: Chen, Michael Chun-Yuan, Di Francesco, J., Johnstone, D., Sadavoy, S., Hatchell, J., Mottram, J. C., Kirk, H., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Pezzuto, S., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Schneider-Bontemps, N., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., Zhu, M., Chen, Michael Chun-Yuan, Di Francesco, J., Johnstone, D., Sadavoy, S., Hatchell, J., Mottram, J. C., Kirk, H., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Pezzuto, S., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Schneider-Bontemps, N., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: The dust emissivity spectral index, β, is a critical parameter for deriving the mass and temperature of star-forming structures and, consequently, their gravitational stability. The β value is dependent on various dust grain properties, such as size, porosity, and surface composition, and is expected to vary as dust grains evolve. Here we present β, dust temperature, and optical depth maps of the star-forming clumps in the Perseus Molecular Cloud determined from fitting spectral energy distributions to combined Herschel and JCMT observations in the 160, 250, 350, 500, and 850 μm bands. Most of the derived β and dust temperature values fall within the ranges of 1.0-2.7 and 8-20 K, respectively. In Perseus, we find the β distribution differs significantly from clump to clump, indicative of grain growth. Furthermore, we also see significant localized β variations within individual clumps and find low-β regions correlate with local temperature peaks, hinting at the possible origins of low-β grains. Throughout Perseus, we also see indications of heating from B stars and embedded protostars, as well evidence of outflows shaping the local landscape.

39. The JCMT Gould Belt Survey: SCUBA-2 observations of circumstellar discs in L 1495

Author: Buckle, J. V., Drabek-Maunder, E., Greaves, J., Richer, J. S., Matthews, B. C., Johnstone, D., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Jenness, T., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Salji, C., Tisi, S., Di Francesco, J., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Moriarty-Schieven, G., Rawlings, J., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., Zhu, M., Buckle, J. V., Drabek-Maunder, E., Greaves, J., Richer, J. S., Matthews, B. C., Johnstone, D., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Jenness, T., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Salji, C., Tisi, S., Di Francesco, J., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Moriarty-Schieven, G., Rawlings, J., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We present 850 and 450 μm data from the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey obtained with Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and characterize the dust attributes of Class I, Class II and Class III disc sources in L 1495. We detect 23 per cent of the sample at both wavelengths, with the detection rate decreasing through the Classes from I to III. The median disc mask is 1.6 × 10-3 M⊙, and only 7 per cent of Class II sources have disc masses larger than 20 Jupiter masses. We detect a higher proportion of discs towards sources with stellar hosts of spectral type K than spectral type M. Class II discs with single stellar hosts of spectral type K have higher masses than those of spectral type M, supporting the hypothesis that higher mass stars have more massive discs. Variations in disc masses calculated at the two wavelengths suggest that there may be differences in dust opacity and/or dust temperature between discs with hosts of spectral types K to those with spectral type M.

40. The JCMT Gould Belt survey: a first look at dense cores in Orion B

Author: Kirk, H., Francesco, J. Di, Johnstone, D., Duarte-Cabral, A., Sadavoy, S., Hatchell, J., Mottram, J. C., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., Zhu, M., Kirk, H., Francesco, J. Di, Johnstone, D., Duarte-Cabral, A., Sadavoy, S., Hatchell, J., Mottram, J. C., Buckle, J., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Mowat, C., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Thomas, H., Tothill, N., Viti, S., White, G. J., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We present a first look at the SCUBA-2 observations of three sub-regions of the Orion B molecular cloud: LDN 1622, NGC 2023/2024, and NGC 2068/2071, from the JCMT Gould Belt Legacy Survey. We identify 29, 564, and 322 dense cores in L1622, NGC 2023/2024, and NGC 2068/2071 respectively, using the SCUBA-2 850 μm map, and present their basic properties, including their peak fluxes, total fluxes, and sizes, and an estimate of the corresponding 450 μm peak fluxes and total fluxes, using the FellWalker source extraction algorithm. Assuming a constant temperature of 20 K, the starless dense cores have a mass function similar to that found in previous dense core analyses, with a Salpeter-like slope at the high-mass end. The majority of cores appear stable to gravitational collapse when considering only thermal pressure; indeed, most of the cores which have masses above the thermal Jeans mass are already associated with at least one protostar. At higher cloud column densities, above 1–2 × 1023 cm−2, most of the mass is found within dense cores, while at lower cloud column densities, below 1 × 1023 cm−2, this fraction drops to 10% or lower. Overall, the fraction of dense cores associated with a protostar is quite small (<8%), but becomes larger for the densest and most centrally concentrated cores. NGC 2023/2024 and NGC 2068/2071 appear to be on the path to forming a significant number of stars in the future, while L1622 has little additional mass in dense cores to form many new stars.

41. The JCMT Gould Belt Survey: first results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population

Author: Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M. R., André, Ph., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., Zhu, M., Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M. R., André, Ph., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: In this paper, we present the first observations of the Ophiuchus molecular cloud performed as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) with the SCUBA-2 instrument. We demonstrate methods for combining these data with previous HARP CO, Herschel, and IRAM N2H+ observations in order to accurately quantify the properties of the SCUBA-2 sources in Ophiuchus. We produce a catalogue of all of the sources found by SCUBA-2. We separate these into protostars and starless cores. We list all of the starless cores and perform a full virial analysis, including external pressure. This is the first time that external pressure has been included in this level of detail. We find that the majority of our cores are either bound or virialized. Gravitational energy and external pressure are on average of a similar order of magnitude, but with some variation from region to region. We find that cores in the Oph A region are gravitationally bound prestellar cores, while cores in the Oph C and E regions are pressure-confined. We determine that N2H+ is a good tracer of the bound material of prestellar cores, although we find some evidence for N2H+ freeze-out at the very highest core densities. We find that non-thermal linewidths decrease substantially between the gas traced by C18O and that traced by N2H+, indicating the dissipation of turbulence at higher densities. We find that the critical Bonnor-Ebert stability criterion is not a good indicator of the boundedness of our cores. We detect the pre-brown dwarf candidate Oph B-11 and find a flux density and mass consistent with previous work. We discuss regional variations in the nature of the cores and find further support for our previous hypothesis of a global evolutionary gradient across the cloud from south-west to north-east, indicating sequential star formation across the region.

42. The JCMT Gould Belt Survey: constraints on prestellar core properties in Orion A North

Author: Salji, C. J., Richer, J. S., Buckle, J. V., Hatchell, J., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Tisi, S., Walker-Smith, S., Francesco, J. D., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., Zhu, M., Salji, C. J., Richer, J. S., Buckle, J. V., Hatchell, J., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Tisi, S., Walker-Smith, S., Francesco, J. D., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We employ SCUBA-2 (Submillimetre Common-User Bolometer Array 2) observations of the Orion A North molecular cloud to derive column density and temperature maps. We apply a novel, Hessian-based structural identification algorithm for detection of prestellar cores to these data, allowing for automated generation of the prestellar mass function. The resulting mass function is observed to peak at $1.39^{+0.18}_{{-}0.19} M_{\odot}$, indicating a star-forming efficiency lower limit of ∼14 per cent when compared with the Orion nebula Cluster initial mass function (IMF) peak. Additionally, the prestellar mass function is observed to decay with a high-mass powerlaw exponent $\alpha = 2.53^{+0.16}_{{-}0.14}$, indicating approximate functional similarity with the Salpeter IMF ($\alpha = 2.35$). This result, when combined with the results of previous investigations suggests a regional dependence of the star-forming efficiency.

43. The JCMT Gould Belt Survey: constraints on prestellar core properties in Orion A North

Author: Salji, C. J., Richer, J. S., Buckle, J. V., Hatchell, J., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Tisi, S., Walker-Smith, S., Francesco, J. D., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., Zhu, M., Salji, C. J., Richer, J. S., Buckle, J. V., Hatchell, J., Kirk, H., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pattle, K., Pineda, J. E., Quinn, C., Tisi, S., Walker-Smith, S., Francesco, J. D., Hogerheijde, M. R., Ward-Thompson, D., Bastien, P., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Drabek-Maunder, E., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Holland, W., Joncas, G., Kirk, J. M., Knee, L. B. G., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Thomas, H., Tothill, N., Viti, S., White, G. J., Wilson, C. D., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: We employ SCUBA-2 (Submillimetre Common-User Bolometer Array 2) observations of the Orion A North molecular cloud to derive column density and temperature maps. We apply a novel, Hessian-based structural identification algorithm for detection of prestellar cores to these data, allowing for automated generation of the prestellar mass function. The resulting mass function is observed to peak at $1.39^{+0.18}_{{-}0.19} M_{\odot}$, indicating a star-forming efficiency lower limit of ∼14 per cent when compared with the Orion nebula Cluster initial mass function (IMF) peak. Additionally, the prestellar mass function is observed to decay with a high-mass powerlaw exponent $\alpha = 2.53^{+0.16}_{{-}0.14}$, indicating approximate functional similarity with the Salpeter IMF ($\alpha = 2.35$). This result, when combined with the results of previous investigations suggests a regional dependence of the star-forming efficiency.

44. The JCMT Gould Belt Survey: first results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population

Author: Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M. R., André, Ph., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., Zhu, M., Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Di Francesco, J., Hogerheijde, M. R., André, Ph., Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: In this paper, we present the first observations of the Ophiuchus molecular cloud performed as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) with the SCUBA-2 instrument. We demonstrate methods for combining these data with previous HARP CO, Herschel, and IRAM N2H+ observations in order to accurately quantify the properties of the SCUBA-2 sources in Ophiuchus. We produce a catalogue of all of the sources found by SCUBA-2. We separate these into protostars and starless cores. We list all of the starless cores and perform a full virial analysis, including external pressure. This is the first time that external pressure has been included in this level of detail. We find that the majority of our cores are either bound or virialized. Gravitational energy and external pressure are on average of a similar order of magnitude, but with some variation from region to region. We find that cores in the Oph A region are gravitationally bound prestellar cores, while cores in the Oph C and E regions are pressure-confined. We determine that N2H+ is a good tracer of the bound material of prestellar cores, although we find some evidence for N2H+ freeze-out at the very highest core densities. We find that non-thermal linewidths decrease substantially between the gas traced by C18O and that traced by N2H+, indicating the dissipation of turbulence at higher densities. We find that the critical Bonnor-Ebert stability criterion is not a good indicator of the boundedness of our cores. We detect the pre-brown dwarf candidate Oph B-11 and find a flux density and mass consistent with previous work. We discuss regional variations in the nature of the cores and find further support for our previous hypothesis of a global evolutionary gradient across the cloud from south-west to north-east, indicating sequential star formation across the region.

45. POL-2: The SCUBA-2 Polarimeter

Author: Bastien, P., Bissionnetee, E., Simon, A., Coude, S., Ade, Peter A. R., Savini, Giorgio, Pisano, G., Leclerc, M., Bernier, S., Landry, J., Houde, M., Hezareh, T., Naylor, D. A., Gom, B. G., Jenness, T., Berry, D. S., Johnstone, D., Matthews, B. C., Bastien, P., Bissionnetee, E., Simon, A., Coude, S., Ade, Peter A. R., Savini, Giorgio, Pisano, G., Leclerc, M., Bernier, S., Landry, J., Houde, M., Hezareh, T., Naylor, D. A., Gom, B. G., Jenness, T., Berry, D. S., Johnstone, D., and Matthews, B. C.
Abstract: The SCUBA-2 polarimeter is expected to be the most sensitive instrument for the detection of polarized radiation in the submillimeter regime. This will be possible by taking advantage of the extra sensitivity, imaging speed and improved image fidelity of the new SCUBA-2 camera which is being commissioned now for use on the James-Clerk-Maxwell Telescope (JCMT). POL-2 construction is now complete and the instrument has been delivered and installed on the telescope. A general update of the instrument and its capabilities are presented. Its optical and mechanical characteristics are summarized and the expected performance is compared to previous polarimetry experiments on the JCMT. Rapid modulation to eliminate atmospheric effects is being implemented.

46. The JCMT Gould Belt Survey: first results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population

Author: Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Francesco, J. Di, Hogerheijde, M. R., André, Ph, Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., Zhu, M., Pattle, K., Ward-Thompson, D., Kirk, J. M., White, G. J., Drabek-Maunder, E., Buckle, J., Beaulieu, S. F., Berry, D. S., Broekhoven-Fiene, H., Currie, M. J., Fich, M., Hatchell, J., Kirk, H., Jenness, T., Johnstone, D., Mottram, J. C., Nutter, D., Pineda, J. E., Quinn, C., Salji, C., Tisi, S., Walker-Smith, S., Francesco, J. Di, Hogerheijde, M. R., André, Ph, Bastien, P., Bresnahan, D., Butner, H., Chen, M., Chrysostomou, A., Coude, S., Davis, C. J., Duarte-Cabral, A., Fiege, J., Friberg, P., Friesen, R., Fuller, G. A., Graves, S., Greaves, J., Gregson, J., Griffin, M. J., Holland, W., Joncas, G., Knee, L. B. G., Könyves, V., Mairs, S., Marsh, K., Matthews, B. C., Moriarty-Schieven, G., Rawlings, J., Richer, J., Robertson, D., Rosolowsky, E., Rumble, D., Sadavoy, S., Spinoglio, L., Thomas, H., Tothill, N., Viti, S., Wouterloot, J., Yates, J., and Zhu, M.
Abstract: In this paper, we present the first observations of the Ophiuchus molecular cloud performed as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) with the SCUBA-2 instrument. We demonstrate methods for combining these data with previous HARP CO, Herschel, and IRAM N2H+ observations in order to accurately quantify the properties of the SCUBA-2 sources in Ophiuchus. We produce a catalogue of all of the sources found by SCUBA-2. We separate these into protostars and starless cores. We list all of the starless cores and perform a full virial analysis, including external pressure. This is the first time that external pressure has been included in this level of detail. We find that the majority of our cores are either bound or virialized. Gravitational energy and external pressure are on average of a similar order of magnitude, but with some variation from region to region. We find that cores in the Oph A region are gravitationally bound prestellar cores, while cores in the Oph C and E regions are pressure-confined. We determine that N2H+ is a good tracer of the bound material of prestellar cores, although we find some evidence for N2H+ freeze-out at the very highest core densities. We find that non-thermal linewidths decrease substantially between the gas traced by C18O and that traced by N2H+, indicating the dissipation of turbulence at higher densities. We find that the critical Bonnor-Ebert stability criterion is not a good indicator of the boundedness of our cores. We detect the pre-brown dwarf candidate Oph B-11 and find a flux density and mass consistent with previous work. We discuss regional variations in the nature of the cores and find further support for our previous hypothesis of a global evolutionary gradient across the cloud from south-west to north-east, indicating sequential star formation across the region

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Journal

Database

Publisher

46 results on '"Coude, S."'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources