of my Books and publications
out some of my pictures
The press release of
our Naturalization Ceremony at the VLA
(select one from the menu)
I am a scientist-astronomer at the National Radio Astronomy Observatory
(NRAO). When I joined NRAO in 2007, I primarily worked
on the scientific-astronomical commissioning of the Expanded Very Large Array (EVLA). The project was concluded
in Fall 2012, and the array was named the Karl G. Jansky Very Large Array (VLA) to honor
the founder of Radio Astronomy. The VLA is the world's dominant cm-wavelength radio telescope and most sensitive interferometer operating between 1 and
50 GHz. From 2015 to 2020 I served as the lead of the VLA/VLBA
Scientific User Support group. Since 2020 I have been
serving as the division head for the VLA/VLBA Science Support.
Before joining NRAO in 2007, I was an astronomer at the world's
largest radio-radar telescope, the
305-m (1000 ft) Arecibo Radio Telescope of the
National Astronomy and Ionosphere Center
(NAIC). Arecibo's 900 ton platform collapsed on Dec.
1, 2020 (video),
bringing an end to a very productive scientific journey that spanned
57 years. I personally used this remarkable telescope for two
decades as a single dish radio telescope and as an element in VLBI
arrays. I will for sure miss it!
My research is focused on high angular resolution radio observations of
extragalactic objects known as
LIRGs (Luminous Infrared Galaxies) and ULIRGs (Ultra Luminous Infrared
Galaxies), to study both the structure and the kinematics of the
central regions in these galaxies. This research includes imaging of
these galaxies in radio continuum, in HI 21 cm absorption, and in
OH 18 cm megamaser emission.
For this research, and in order to study the nuclear active regions of
these galaxies at very high spatial resolution, I mainly use the Very
Long Baseline Array (VLBA)
of the NRAO.
However, the radio emission from these IR galaxies is very weak.
Therefore, in order to have successful
observations, the Very Large Array(VLA)
of the NRAO,
with its twenty seven 25-meter antennas, participates in these
In some of these observations, the giant 305-meter
Arecibo radio telescope was used along with both the VLBA
and the VLA.
Thanks to the enhanced observational capabilities of the VLA, I have
become actively involved in magnetic field studies through Methanol
masers. This work has led us to discover the Zeeman effect in three
Class I methanol maser transitions: at 25, 36, and 44 GHz. Visit my
page to check the discovery and the follow-up papers on this topic
(through the NASA ADS).
I am also involved in the COSMOS HI Large Extragalactic Survey (CHILES). This is a blind HI survey to detect 21 cm neutral hydrogen emission up to a
redshift of 0.45 using the new capabilities of the VLA. The observations of the survey (1000
hours) have concluded already. In 2016, and using the first 178 hours of the VLA CHILES observations we have already broken the record
of the highest redshift HI 21 cm detection in emission (see the NRAO press
release on this topic).
I am actively involved in VLA and sensitive VLBI imaging of the radio continuum emission from very high redshift
quasars, both radio-loud and radio-quiet. These quasars are believed to be near the epoch of re-ionization,
i. e., when the first stars and galaxies started to form (less than 1 billion years after
the Big Bang). The current redshift record for a radio-loud quasar, which has also been
detected and imaged with VLBI, is z=6.82 (see the NRAO press release on this
topic). We also expanded this type of work to sub-millimeter
galaxies (SMGs) at z~2-3 to study and determine their nuclear power sources (AGN vs. starburst).
If you are interested in history,
then you should read about the history of my
people, the Armenian people, a real but painful example of
a nation's survival for thousands of years (3500 years!). Here are some
The Armenian Genocide:
The first genocide of the 20th
century. During the Genocide, 1.5 million armenians perished in the turkish occupied Western Armenia. To read more, visit the
Armenian National Institute
You can also read about the armenian genocide at the following web sites:
Wikipedia on Armenian Genocide
ArmenianHouse.org: an electronic library featuring a huge collection of documents on Armenian literature, history, religion and anything else Armenia-related
You can reach me by sending an email
updated: Monday, 30-May-2022 12:49:28 MDT