1. ERAU 1-m Observing Proposal Standard Proposal Panel: For Official Review
Date: March 24, 2015 Category: Galactic Photometry
Determination of Star Formation Rates of H-II Regions within
Messier 106 (Seyfert II Galaxy)
PI: Space Girl Status: P Affil.: Embry Riddle Aeronautical University
600 S Clyde Morris Blvd,
Daytona Beach, FL 32114 USA
Email: *******@my.erau.edu Phone: (219) 577-3737 FAX: (386) 226-6621
Abstract
H-II regions within galaxies (and nebulae) are optimal targets of observation when looking into
stellar nurseries and star formation in the universe and are constantly being studied by astronomers.
They are excellent sources of data which provide important information on how many stars are
being created in relation to factors determined by, in this case, galactic photometry.
For the purpose of better understanding the undergoing processes that occur for the formation of
stars that are created within the universe, I have chosen to perform photometry on Messier 106 in
order to study its H-II regions and potentially determine the star formation rate and number of stars
being formed within a certain number of its H-II regions. Utilizing photometry will help determine
the surface brightness and temperature of a galaxy and/or its prominent H-II regions and by
focusing on the use of the Hα and infrared filters, I will be able to analyze the ionization processes
and determine the star formation rate occurring within a select few H-II regions. This research will
expand upon my knowledge of H-II regions and their importance in the creation of new stars in
the universe.
As will be stated in this proposal to use Embry-Riddle Aeronautical University’s Ritchey-Chretien
1-meter telescope, I ask to perform photometry on Messier 106 using the STX-16803 instrument
in order to study the galaxy’s H-II regions and determine the star formation rate occurring within.
Summary of Request
Telescope Instrument No. Nights Optimal Months
RC 1-m STX-16803 14 Jan - Apr

2. 2
Scientific Justification
There are numerous galaxies that have what are known as H-II regions which can be defined as
interstellar matter consisting of ionized hydrogen atoms. In 1610, Nicolas-Claude Fabri de Peiresc
discovered the first known H-II region in the Orion Nebula. These regions are primarily
characterized by their massive O-type and B-type stars and amount of ionized atomic hydrogen
found within and can give birth to thousands of stars over the course of millions of years. When
these large amounts of interstellar matter collapse, star formation occurs. To further our
understanding of these regions and their importance to the formation of stars in the universe, it is
beneficial to study the undergoing processes and formation rate of the H-II regions within galaxies
such as Messier 106.
Messier 106 (also known as NGC 4258) is a spiral Seyfert 2 galaxy located within the constellation
Canes Venatici; it has a right ascension of 12 hours 18 minutes 57.620 seconds (J2000), a
declination of +47 degrees 18 minutes and 13.39 seconds (J2000), and a redshift of 462.27 km/s.
It is about 22 to 25 million light years away and has an apparent magnitude of 8.4 which makes it
a relatively good target for observing because of its brightness and size. Looking at previous data,
Messier 106 exhibits regions, both north and south of the nucleus, attributed to being supergiant
H-II regions where massive star formation is occurring. Using photometry to study such H-II
regions in Messier 106, should it be found that temperatures are high and the luminosity of the
ionizing stars is significant, the star formation rate will potentially be easier to determine given the
highly luminous state and ionization degree of the regions. Thus, shedding light on the undergoing
processes that cause star formation in the universe and the number of stars being in comparison to
different H-II regions within Messier 106.
Studying H-II regions in galaxies is important in understanding stellar formation as well as
galactic formation. Comparing regions of star formation will give insight into the factors that
affect the ionization processes and creation of new stars.
References
Beckman, John E & Leonel Gutierrez. “The physics of the HII regions: the photoionization
equilibrium in the HII regions of M51.”
http://www.slac.stanford.edu/econf/C07091016/papers/LNEAIII-Gutierrez.pdf.
“H II region.” http://en.wikipedia.org/wiki/H_II_region.
Mathis, John S. “H II region.” Encyclopedia Britannica.
http://www.britannica.com/EBchecked/topic/250567/H-II-region.
“M 106 – Seyfert 2 Galaxy.” SIMBAD. http://simbad.u-strasbg.fr/simbad/sim-
id?Ident=messier+106&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id.
“Messier 106 – Spiral Galaxy (Type Sbp).” Cool Cosmos.
http://coolcosmos.ipac.caltech.edu/cosmic_classroom/multiwavelength_astronomy/multiwavelen
gth_museum/m106.html.

3. 3
Experimental Design and Technical Description
The goal of this study is to obtain a higher understanding of star formation and how different
factors affect formation rates such as size, distances, temperatures, and brightness. I want to
determine the star formation rates of certain H-II regions given the previously stated factors
observed under the Hα and infrared filters, and thus, compare the number of stars being formed
within different H-II regions of Messier 106.
Messier 106 is optimally seen in the spring, specifically during the month of March. These
observations will all be dependent upon favorable weather conditions for optimal operation of the
telescope and instrument. Given the total time available for observation, I request 14 days and 2
hours per night for an allotted time of 28 hours of operation of the telescope for positioning,
focusing, etc., as well as data imaging of Messier 106 and gathering a good amount of biases and
dark flats. Given the distance of the galaxy, I am requesting these hours based on the exposure
times needed in order to collect the most efficient data possible. Exposure times will last between
10-40 minutes each under Hα and infrared filters.
The allotted number of hours are requested in order to compensate for preparation time, slewing,
and utilization of the telescope and instrument.