Zobrazeno 1 - 10
of 40
pro vyhledávání: '"Derck P. Smits"'
Publikováno v:
The Astronomical Journal, Vol 166, Iss 1, p 26 (2023)
C -band Mueller matrices for the Green Bank Telescope are presented here which enable on-sky Stokes parameters for point sources at the beam center to be determined. Standard calibrators, 3C 138 and 3C 286, were observed using the Spider program to s
Externí odkaz:
https://doaj.org/article/183f25d937ab45a08c5d1a8dc8b20114
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 502:5658-5667
The first confirmed periodically varying 6.031 and 6.035 GHz hydroxyl masers are reported here. They vary contemporaneously with the 6.7 GHz methanol masers in G323.459–0.079. The 1.665 GHz hydroxyl and 12.2 GHz methanol masers associated with G323
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c5d8ac91a7a284781ee96370a6b15a9f
https://doi.org/10.1093/mnras/stab462
https://doi.org/10.1093/mnras/stab462
Autor:
Derck P. Smits, P. L. Skelton
Publikováno v:
New Astronomy. 67:53-66
Variable stars in HLF 356 identified from plates taken at Harvard Observatory southern station in the 1930s are characterised using data from the ASAS, SuperWASP and Catalina Sky Survey databases. Very little work has been done on these variables sin
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::82c32f1e71913d507393c7af29f47ad9
https://doi.org/10.1016/j.newast.2018.09.006
https://doi.org/10.1016/j.newast.2018.09.006
Autor:
Andri Prozesky, Derck P. Smits
Publikováno v:
Monthly Notices of the Royal Astronomical Society.
Atomic hydrogen masers occur in recombination plasmas in sufficiently dense HII regions. These hydrogen recombination line (HRL) masers have been observed in a handful of objects to date and the analysis of the atomic physics involved has been rudime
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::dd33a2d5761953bc86a79834eff51ecf
https://doi.org/10.1093/mnras/stz3174
https://doi.org/10.1093/mnras/stz3174
Autor:
Todd R. Hunter, P J Banda, C J Thesner, G. C. MacLeod, James O. Chibueze, S. P. van den Heever, J D Paulsen, Derck P. Smits, Crystal L. Brogan, Sharmila Goedhart
As a product of the maser monitoring program with the 26m telescope of the Hartebeesthoek Radio Astronomy Observatory (HartRAO), we present an unprecedented, contemporaneous flaring event of 10 maser transitions in hydroxyl, methanol, and water that
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c6706a19d28044ed433ef4bf7b8dc2de
Autor:
G. C. MacLeod, Claudia Cyganowski, Rachel Friesen, Claire J. Chandler, Remy Indebetouw, Todd R. Hunter, Tomoya Hirota, Crystal L. Brogan, Derck P. Smits, James O. Chibueze
Publikováno v:
NASA Astrophysics Data System
We report the first sub-arcsecond VLA imaging of 6 GHz continuum, methanol maser, and excited-state hydroxyl maser emission toward the massive protostellar cluster NGC6334I following the recent 2015 outburst in (sub)millimeter continuum toward MM1, t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1202b16242c1883d01f260d48c74ee43
Autor:
Andri Prozesky, Derck P. Smits
Calculations of hydrogen departure coefficients using a model with the angular momentum quantum levels resolved that includes the effects of external radiation fields are presented. The stimulating processes are important at radio frequencies and can
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::18ecbc81fbb39001f32f80e5e1bce712
Autor:
S. Belay Goshu, Derck P. Smits
Publikováno v:
Applied Mathematics. :440-446
We present the dependence of electron temperature fluctuations of O++ and H+ by the chemical abundances of oxygen and nitrogen. Models assume that hydrogen density is uniform in one case and non uniform in the second case, which vary with the distanc
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::416b96cb519e84cf062dae6f68cce667
https://doi.org/10.4236/am.2015.62041
https://doi.org/10.4236/am.2015.62041
Autor:
Derck P. Smits, S. Belay Goshu
Publikováno v:
Journal of Materials Science and Chemical Engineering. :7-16
We present phoionization model calculations of ionization fraction of hydrogen, helium and oxy-gen at low density of photoionized nebulae using the photoionization code CLOUDY. The ionization parameter is between -2.0 ≤ log(U) ≤ 1.0, and we study
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7de290f9653b854cec6c73d0fc191c34
https://doi.org/10.4236/msce.2015.34002
https://doi.org/10.4236/msce.2015.34002
Autor:
Belay S. Goshu, Derck P. Smits
Publikováno v:
Journal of Materials Science and Chemical Engineering. :21-29
In current photoionization models, determination of the ionization structure of the nebulae is a crucial part of the calculations for non-uniform hydrogen density. We have been tried to compute temperature fluctuations of electron and electron densit
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e826c275220035b206760e2ed5c1ec87
https://doi.org/10.4236/msce.2015.38004
https://doi.org/10.4236/msce.2015.38004