Results 11 to 20 of about 1,144,964 (311)

PHANGS–JWST First Results: Destruction of the PAH Molecules in H ii Regions Probed by JWST and MUSE

The Astrophysical Journal Letters, 2023
Polycyclic aromatic hydrocarbons (PAHs) play a critical role in the reprocessing of stellar radiation and balancing the heating and cooling processes in the interstellar medium but appear to be destroyed in H ii regions.
Oleg V. Egorov, Kathryn Kreckel, Karin M. Sandstrom, Adam K. Leroy, Simon C. O. Glover, Brent Groves, J. M. Diederik Kruijssen, Ashley. T. Barnes, Francesco Belfiore, F. Bigiel, Guillermo A. Blanc, Médéric Boquien, Yixian Cao, Jérémy Chastenet, Mélanie Chevance, Enrico Congiu, Daniel A. Dale, Eric Emsellem, Kathryn Grasha, Ralf S. Klessen, Kirsten L. Larson, Daizhong Liu, Eric J. Murphy, Hsi-An Pan, Ismael Pessa, Jérôme Pety, Erik Rosolowsky, Fabian Scheuermann, Eva Schinnerer, Jessica Sutter, David A. Thilker, Elizabeth J. Watkins, Thomas G. Williams   +32 more
doaj   +2 more sources

Ionized gas kinematics in bipolar H ii regions [PDF]

Monthly Notices of the Royal Astronomical Society, 2018
14 pages and 9 figures.
Hannah S Dalgleish, Steven N Longmore, Thomas Peters, Jonathan D Henshaw, Joshua L Veitch-Michaelis, James S Urquhart   +5 more
core   +10 more sources

Wolf - Rayet Stars in H II Regions [PDF]

Monthly Notices of the Royal Astronomical Society, 1971
A catalogue of WR stars coincident with H II regions is presented. Approximately 44 per cent of the WR stars surveyed are found to be 'possibly' associated with nebulosity while association is considered to be 'probable' for 25 per cent of the cases.
Crampton, David
openaire   +3 more sources

Stellar associations powering H II regions - I. Defining an evolutionary sequence

, 2023
Connecting the gas in H II regions to the underlying source of the ionizing radiation can help us constrain the physical processes of stellar feedback and how H II regions evolve over time. With PHANGS–MUSE, we detect nearly 24 000 H II regions across 19
Pan, Hsi-an
core   +1 more source

A Large-Scale, Low-Frequency Murchison Widefield Array Survey of Galactic H ii Regions between 260° [PDF]

, 2016
We have compiled a catalogue of H ii regions detected with the Murchison Widefield Array between 72 and 231 MHz. The multiple frequency bands provided by the Murchison Widefield Array allow us identify the characteristic spectrum generated by the thermal
Kaplan, D. L., Prabu, T, McWhirter, S. R., Cappallo, R. J., Ord, SM, Procopio, P, Hindson, L, Williams, C. L., Morales, M., Mckinley, B, Morgan, J., Greenhill, L., Hindson, L., Williams, A., Hurley-Walker, N., Staveley-Smith, L, Lonsdale, C. J., Tingay, SJ, Kaplan, D., Mitchell, DA, Williams, A, Prabu, T., Wu, C., Lonsdale, C., Callingham, JR, Su, H, For, BQ, Srivani, K. S., Johnston-Hollitt, M., Dwarakanath, K., Udaya Shankar, N, Cappallo, R., Ord, S. M., Mitchell, D., Morales, M. F., Williams, C., Callingham, J., Procopio, P., Hurley-Walker, N, Lenc, E, Lonsdale, CJ, Wu, C, Mitchell, D. A., BERNARDI, GIANNI, Subrahmanyan, R., For, B., Tingay, S. J., Webster, R., Kapińska, A. D., Wayth, RB, Greenhill, L. J., Hazelton, B. J., Briggs, F., Williams, CL, Deshpande, A., Shankar, N. Udaya, Shankar, N., Dwarakanath, K. S., Bell, M, Subrahmanyan, R, For, B. -Q, Webster, R. L., Zheng, Q., Deshpande, AA, Offringa, A, For, B.-Q, Hancock, P, For, B. -Q., Srivani, K., Webster, RL, Kaplan, DL, Deshpande, A. A., Bell, M., Oberoi, D, Morgan, E., Gaensler, B. M., Staveley-Smith, L., Mckinley, B., Dwarakanath, KS, Cappallo, RJ, Gaensler, B., Zheng, Q, Hancock, P., Morales, MF, UdayaShankar, N., Johnston-Hollitt, M, Srivani, KS, McWhirter, S., Callingham, J. R., Hurley-Walker, Natasha, Wayth, R. B., Ord, S., Hazelton, BJ, Kapinska, A., Greenhill, LJ, Lenc, E., Gaensler, BM, Briggs, F, Bowman, J. D., Offringa, A., Oberoi, D., Morgan, E, Bowman, JD, Bernardi, G., Tingay, Steven, McWhirter, SR, Hazelton, B., Kapinska, AD, Wayth, Randall, Morgan, J, Su, H., Bernardi, G, Bowman, J.   +112 more
core   +1 more source

Ne II Observations of Gas Motions in Compact and Ultracompact H II Regions [PDF]

, 2008
We present high spatial and spectral resolution observations of 16 Galactic compact and ultracompact H II regions in the [Ne II] 12.8 mu m fine-structure line.
Thomas K. Greathouse, Lacy, John H., Daniel T. Jaffe, Zhu, Qing-Feng, Jaffe, Daniel T., Matthew J. Richter, Richter, Matthew J., Qing‐Feng Zhu, Greathouse, Thomas K., John H. Lacy   +9 more
core   +1 more source

Hydrodynamical models of cometary H ii regions [PDF]

, 2017
We have modelled the evolution of cometary H ii regions produced by zero-age main-sequence stars of O and B spectral types, which are driving strong winds and are born off-centre from spherically symmetric cores with power-law (α = 2) density slopes.
Steggles, HG, Hoare, MG, M. G. Hoare, J. M. Pittard, Pittard, JM, H. G. Steggles   +5 more
core   +1 more source

Intergalactic H II regions discovered in SINGG [PDF]

, 2004
A number of very small isolated H II regions have been discovered at projected distances up to 30 kpc from their nearest galaxy. These H II regions appear as tiny emission-line objects in narrowband images obtained by the NOAO Survey for Ionization in ...
Freeman, K. C., Koribalski, B. S., Zwaan, M. A., Smith, R. C., Meyer, M. J., Knezek, P. M., Heckman, T. M., Ryan-Weber, E. V., Kilborn, V. A., Kennicutt, R. C., Webster, R. L., Oey, M. S., Meurer, G. R., Hanish, D., Staveley-Smith, L., Drinkwater, M. J., Ferguson, H. C., Putman, M. E.   +17 more
core   +1 more source

Properties of H II region populations in galaxies. II - The H II region luminosity function

The Astrophysical Journal, 1989
H-alpha emission-line fluxes have been measured for all of the detected H II regions in 30 nearby spiral and irregular galaxies, and these data are used to study the behavior of the H II region luminosity functions (LFs). In most galaxies, the LF is well represented by a power law function.
Robert C., Jr. Kennicutt, B. Kevin Edgar, Paul W. Hodge   +2 more
openaire   +1 more source

Interstellar Bubbles in Two Young H II Regions [PDF]

, 2001
peer reviewedMassive stars are expected to produce wind-blown bubbles in the interstellar medium; however, ring nebulae, suggesting the existence of bubbles, are rarely seen around main-sequence O stars.
Nazé, Yaël, Rosado, Margarita, Points, Sean D, Chen, C-H Rosie, Danforth, Charles W, Chu, You-Hua   +5 more
core   +1 more source