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OH MASERS / MEGAMASERS
Project: GBT 2 Jim Braatz Rachel Olsten, Christopher AЯorve, Laura GСmez, Marta Cueto, Myriam Cruz

OUTLINE
I. II. III. IV. V.

Definitions Science Background Observations Results Summary


Definitions
What is a Maser?
A maser is an optical amplifier that produces coherent microwaves due to stimulated emissions. A maser line is the brightest spectral line in the radio universe. It highlights stars forming regions, dense circumstellar shells around evolved stars as well as circumnuclear disk around blackholes of galactic nuclei.

Mi

crowav e

Am

plification by

Stim

ulated

Em

issions of

Radi

ation

W hat is a megamaser? A megamaser is an extragalactic source with an unprecedented isotropic luminosity of ~103L It is a million times more luminous than nearby sources of masers. Almost 100 OH type and 60 H2O type megamasers have been detected b y this time.



Science Background
Masers were discovered more than 25 years ago. Research in this astronomical area has experience great growth due to interferometric techniques. Masers are used for the study of astronomical enviroments, where radiation is created and in through which it propagates.*

Science Background
Objects showing masers emissions:
Stars Galaxies Star forming regions Supernovas


Science Background
Types of masers: OH H2O S iO CH3OH NH3 OH Megamasers
Most of these molecules are produced duri ng the birth process of a star due to powerful shocks that generates strong stellar winds with high velocity that runs into high density magnetized material.*

Observations
Sources observed:
W 3OH TCom RHya W Leo Arp220 Mrk231 IRAS 1017 3+ S S E E 0828 tar forming region Star tar Star xtragalactic source xtragalactic source* Extragalactic source*

*These sources w ere observed w ith no clear results due to possible RFI and/or noise.


GRAPHICS

SOURCE: W3OH (STAR FORMING REGION)


SOURCE: TCOM (STAR)

SOURCE: RHYA (STAR)


SOURCE: WLEO (STAR)


SOURCE: ARP220 (EXTRAGLACTIC SOURCE)

Results
SOURCE S W 3OH TCom RH ya W Leo Arp220 DIST ANCE S (pc) 2200 1253 617 1220 Z=0.018 TYPE SFR * * * EG INT. FLUX (Jy Km/s) 432.34 1.97 17.05 1.34 52.20 L/L (SNR) 3.6 10(6.8) 5.2 10(14.9) 1.1 10(5.9) 3.4 10(12.7)
6

Tsys (K ) 41.52

RM S/Calc

0.02/0.017 0.01/0.009 0.01/0.008 0.01/0.009 0.008/0.006

9

15.05
8

16.67
9

15.17 16.33

512 (701.9)

Table 1. Integrated fluxes and luminosities.


Summary
Statistical analysis of masers can provide great information about the stages and evolutionary schemes of the stellar population. Information that, otherwise, will stay completely hidden by thick dust shells in the universe.

Perspective
Great knowledge has been gathered from this project and we all know that this experience will be of impact and contribution to our professional development.


References
Benson's Catalog (1990; ApJS...74...911) Braatz, Jim, et. als; 2005 Summer School Project Abstract Elitzur, M.; Astronomical Masers; Annu. Rev. Astron. Astrophys.; 1992. 30:75-112* Engle's Catalog (1979; 26AS...36...337) www.damir.iem.csic.es/PARDO http://ub.rug.nl/eldoc/dis/science/h.r.kloekner/c3.pdf http://cdsweb.u-strasbg.fr/viz-bin/VizieR?source=J/A+A/397/213