Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/ArayatagA2411tp.ps Дата изменения: Wed Jun 11 18:58:47 2008 Дата индексирования: Wed Jan 14 08:23:40 2009 Кодировка: Поисковые слова: vallis

Proposal Identification No.: A2411 Date Received: 2008­Jun­02 17:21:10
Technical Page
Proposal Type: Long­term
General Category: Astronomy
Sub­Category: Spectroscopy
Observation Category: Galactic
Total Time Requested: 37 Hours
Minimum Useful Time: 1
Proposal Title: Periodic Maser Flares in IRAS18566+0408: Continuing the Arecibo Monitoring
Program
ABSTRACT:
Using Arecibo we discovered H2CO maser emission in IRAS18566+0408, a very young massive stellar object.
Subsequent observations resulted in the detection of the first short­term flare of an H2CO maser. Two years ago we
started a monitoring program of the H2CO maser with Arecibo that, together with VLA observations, resulted in
the detection of three more flare events. The flares appear to be periodic; we have discovered the first periodic
H2CO maser flare system. We also discovered correlated variability between the H2CO and CH3OH masers in the
region. After a comprehensive study of IRAS18566+0408 using Arecibo, (E)VLA, MERLIN, GBT, as well as
Spitzer, we have found evidence that the flares are tracing changes in the infrared field, perhaps caused by
pulsations of the massive protostar. If this is confirmed, the periodic maser flares may be giving us fundamental
new insight into the structure of massive protostars. Here we propose to continue our Arecibo monitoring program
to study the next flare event with high temporal resolution, and investigate long term changes in the periodicity
and peak intensity of the flares.
Name Institution E­mail Phone Student
Esteban D Araya University of New
Mexico
earaya@nrao.edu 505 252 3747 no
Remote Observing Request
Observer will travel to AO
X Remote Observing
In Absentia (instructions to oper­
ator)
Instrument Setup
C C­high
Atmospheric Observation Instruments:
1

Special Equipment or setup: none
RFI Considerations
Frequency Ranges Planned
4820 ­ 4840 (H2CO 6cm)
6660 ­ 6680 (CH3OH 6.7 GHz)
2