Search Results - "Heever, S P van den"

Periodic variability of the mainline hydroxyl masers in G9.62+0.20E by Goedhart, S, van Rooyen, R, van der Walt, D J, Maswanganye, J P, Sanna, A, MacLeod, G C, van den Heever, S P

“…Abstract We present the results of a monitoring campaign using the KAT-7 and HartRAO 26 m telescopes, of hydroxyl, methanol, and water vapour masers associated…”
Get full text

Synchronized periodic maser flares of multiple OH and CH3OH lines in G323.459–0.079 by MacLeod, G C, Smits, Derck P, Green, J A, van den Heever, S P

“…ABSTRACT 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…”
Get full text

Powerful bursts of water masers towards G25.65+1.05 by Volvach, L N, Volvach, A E, Larionov, M G, MacLeod, G C, van den Heever, S P, Wolak, P, Olech, M

“…ABSTRACT The results of long-term monitoring of the Galactic 22.2 GHz water masers associated with G25.65+1.05 using several telescopes are presented. We…”
Get full text

A heatwave of accretion energy traced by masers in the G358-MM1 high-mass protostar by Burns, R. A., Sugiyama, K., Hirota, T., Kim, Kee-Tae, Sobolev, A. M., Stecklum, B., MacLeod, G. C., Yonekura, Y., Olech, M., Orosz, G., Ellingsen, S. P., Hyland, L., Caratti o Garatti, A., Brogan, C., Hunter, T. R., Phillips, C., van den Heever, S. P., Eislöffel, J., Linz, H., Surcis, G., Chibueze, J. O., Baan, W., Kramer, B.

“…High-mass stars are thought to accumulate much of their mass via short, infrequent bursts of disk-aided accretion 1 , 2 . Such accretion events are rare and…”
Get full text

A masing event in NGC 6334I: contemporaneous flaring of hydroxyl, methanol, and water masers by MacLeod, G C, Smits, D P, Goedhart, S, Hunter, T R, Brogan, C L, Chibueze, J O, van den Heever, S P, Thesner, C J, Banda, P J, Paulsen, J D

Get full text

Detection of new methanol maser transitions associated with G358.93−0.03 by MacLeod, G C, Sugiyama, K, Hunter, T R, Quick, J, Baan, W, Breen, S L, Brogan, C L, Burns, R A, Caratti o Garatti, A, Chen, X, Chibueze, J O, Houde, M, Kaczmarek, J F, Linz, H, Rajabi, F, Saito, Y, Schmidl, S, Sobolev, A M, Stecklum, B, van den Heever, S P, Yonekura, Y

“…ABSTRACT We report the detection of new 12.178, 12.229, 20.347, and 23.121 GHz methanol masers in the massive star-forming region G358.93−0.03, which are…”
Get full text

Identifying Zeeman pairs of hydroxyl masers in NGC 6334I-MM3 via velocity drift by MacLeod, G C, Smits, D P, Hunter, T R, Brogan, C, Chibueze, J O, van den Heever, S P

“…ABSTRACT A new tool to identify possible Zeeman pairs is presented here: the right circularly polarized (RCP) and left circularly polarized (LCP) components of…”
Get full text

Monitoring a methanol maser flare associated with the massive star-forming region G358.93–0.03 by Volvach, A E, Volvach, L N, Larionov, M G, MacLeod, G C, van den Heever, S P, Sugiyama, K

“…ABSTRACT We report the earliest detection of the 19.967-GHz [transition 21–30E (t = 0)] methanol maser associated with the massive star-forming region…”
Get full text

Modelling of the multitransition periodic flaring in G9.62+0.20E by Rajabi, F, Houde, M, MacLeod, G C, Goedhart, S, Tanabe, Y, van den Heever, S P, Wyenberg, C M, Yonekura, Y

“…ABSTRACT We present detailed modelling of periodic flaring events in the 6.7 GHz and 12.2 GHz methanol lines as well as the OH 1665 MHz and 1667 MHz…”
Get full text

Ammonia masers towards G 358.931−0.030 by McCarthy, T P, Breen, S L, Kaczmarek, J F, Chen, X, Parfenov, S, Sobolev, A M, Ellingsen, S P, Burns, R A, MacLeod, G C, Sugiyama, K, Brierley, A L, van den Heever, S P

“…ABSTRACT We report the detection of ammonia masers in the non-metastable (6, 3), (7, 5), and (6, 5) transitions; the latter being the first unambiguous maser…”
Get full text

Discovery of periodic methanol masers associated with G323.46−0.08 by Proven-Adzri, E, MacLeod, G C, Heever, S P van den, Hoare, M G, Kuditcher, A, Goedhart, S

Get full text

Systematic velocity drifts of methanol masers associated with G9.62+0.20E by MacLeod, G C, Chibueze, J O, Sanna, A, Paulsen, J D, Houde, M, van den Heever, S P, Goedhart, S

“…ABSTRACT The source G9.62+0.20E surprises again! Several of the associated 6.7- and 12.2-GHz methanol masers are experiencing contemporaneous and systematic…”
Get full text

Periodic methanol masers: from a colliding wind binary (CWB) perspective by van den Heever, S P, van der Walt, D J, Pittard, J M, Hoare, M G

“…Abstract Since the discovery of periodic class II methanol masers at 6.7 and 12.2 GHz associated with high-mass star formation regions (HMSFRs), a number of…”
Get full text

A Keplerian disk with a four-arm spiral birthing an episodically accreting high-mass protostar by Burns, R. A., Uno, Y., Sakai, N., Blanchard, J., Rosli, Z., Orosz, G., Yonekura, Y., Tanabe, Y., Sugiyama, K., Hirota, T., Kim, Kee-Tae, Aberfelds, A., Volvach, A. E., Bartkiewicz, A., Caratti o Garatti, A., Sobolev, A. M., Stecklum, B., Brogan, C., Phillips, C., Ladeyschikov, D. A., Johnstone, D., Surcis, G., MacLeod, G. C., Linz, H., Chibueze, J. O., Brand, J., Eislöffel, J., Hyland, L., Uscanga, L., Olech, M., Durjasz, M., Bayandina, O., Breen, S., Ellingsen, S. P., van den Heever, S. P., Hunter, T. R., Chen, X.

“…High-mass protostars ( M ⋆  > 8 M ⊙ ) are thought to gain the majority of their mass via short, intense bursts of growth. This episodic accretion is thought to…”
Get full text

A Giant Water Maser Flare in the Galactic Source IRAS 18316-0602 by Vol’vach, L. N., Vol’vach, A.E., Larionov, M.G., MacLeod, G. C., van den Heever, S. P., Wolak, P., Olech, M., Ipatov, A.V., Ivanov, D.V., Mikhailov, A. G., Mel’nikov, A.E., Menten, K., Belloche, A., Weiss, A., Mazumdar, P., Schuller, F.

“…The results of long-term monitoring of the Galactic maser source IRAS 18316–0602 (G25.65+1.05) in the water-vapor line at frequency f = 22.235 GHz (6 16 –5 23…”
Get full text

Author Correction: A Keplerian disk with a four-arm spiral birthing an episodically accreting high-mass protostar by Burns, R. A., Uno, Y., Sakai, N., Blanchard, J., Rosli, Z., Orosz, G., Yonekura, Y., Tanabe, Y., Sugiyama, K., Hirota, T., Kim, Kee-Tae, Aberfelds, A., Volvach, A. E., Bartkiewicz, A., Caratti o Garatti, A., Sobolev, A. M., Stecklum, B., Brogan, C., Phillips, C., Ladeyschikov, D. A., Johnstone, D., Surcis, G., MacLeod, G. C., Linz, H., Chibueze, J. O., Brand, J., Eislöffel, J., Hyland, L., Uscanga, L., Olech, M., Durjasz, M., Bayandina, O., Breen, S., Ellingsen, S. P., van den Heever, S. P., Hunter, T. R., Chen, X.

Get full text

Ammonia masers toward G358.931-0.030 by McCarthy, T. P, Breen, S. L, Kaczmarek, J. F, Chen, X, Parfenov, S, Sobolev, A. M, Ellingsen, S. P, Burns, R. A, MacLeod, G. C, Sugiyama, K, Brierley, A. L, Heever, S. P. van den

“…We report the detection of ammonia masers in the non-metastable (6, 3), (7, 5) and (6, 5) transitions, the latter is the first unambiguous maser detection of…”
Get full text

Multi-frequency VLBI observations of maser lines during the 6.7~GHz maser flare in the high-mass young stellar object G24.33$+$0.14 by Kobak, A, Bartkiewicz, A, Szymczak, M, Olech, M, Durjasz, M, Wolak, P, Chibueze, J. O, Hirota, T, Eislöffel, J, Stecklum, B, Sobolev, A, Bayandina, O, Orosz, G, Burns, R. A, Kim, Kee-Tae, Heever, S. P. van den

“…A&A 671, A135 (2023) Recent studies have shown that 6.7 GHz methanol maser flares can be a powerful tool for verifying the mechanisms of maser production and…”
Get full text

A heat-wave of accretion energy traced by masers in the G358-MM1 high-mass protostar by Burns, R. A, Sugiyama, K, Hirota, T, Kim, Kee-Tae, Sobolev, A. M, Stecklum, B, MacLeod, G. C, Yonekura, Y, Olech, M, Orosz, G, Ellingsen, S. P, Hyland, L, Garatti, A. Caratti o, Brogan, C, Hunter, T. R, Phillips, C, Heever, S. P. van den, Eislöffel, J, Linz, H, Surcis, G, Chibueze, J. O, Baan, W, Kramer, B

“…High-mass stars are thought to accumulate much of their mass via short, infrequent bursts of disk-aided accretion. Such accretion events are rare and difficult…”
Get full text

The evolution of the H2O maser emission in the accretion burst source G358.93-0.03 by Bayandina, O. S, Brogan, C. L, Burns, R. A, Garatti, A. Caratti o, Chibueze, J. O, Heever, S. P. van den, Kurtz, S. E, MacLeod, G. C, Moscadelli, L, Sobolev, A. M, Sugiyama, K, Val'tts, I. E, Yonekura, Y

“…A&A 664, A44 (2022) The massive young stellar object (MYSO) G358.93-0.03-MM1 showed an extraordinary near-infrared- to (sub-)millimetre-dark and…”
Get full text