I am a PhD candidate studying astronomy at Dartmouth College.

I work with Professor Ryan Hickox and his Black Holes and Galaxies research group. My research focuses on magnetically driven accretion onto X-ray pulsars. I am particularly interested in modeling the kinematics and geometry of warped accretion disks, such as those found in Her X-1, LMC X-4, and SMC X-1.

Research: Project Overview

Neutron stars are the dense, highly magnetized cores of massive stars that are left behind after supernova explosions. A neutron star's strong magnetic field accelerates electrons, creating beams of radiation that emanate from the magnetic poles. In a manner similar to a lighthouse signal, this beam of radiation sweeps across space. If this beam intersects Earth, astronomers can detect a burst of light. Because of this behavior, we call such objects pulsars.

X-ray pulsars are a subclass of pulsars that emit X-ray radiation due to accretion. These pulsars are formed in binary systems where the companion star undergoes mass loss. The expelled matter gravitationally falls towards the pulsar, forming an accretion disk. However, when the infalling matter reaches the pulsar's magnetosphere, the magnetic forces dominate the accretion process. As the gas is confined to the pulsar's dipolar magnetic field, the infalling gas heats up and emits X-rays. The process of magnetic accretion, and the response of matter to magnetic fields that are trillions of times stronger than Earth's, is not well understood.

In order to learn more about magnetic accretion mechanisms, I am studying the geometry and kinematics of the warped accretion disks found in LMC X-4 and SMC X-1. Using joint observations from the NuSTAR and XMM-Newton space telescopes, I can observe a complete precession of the accretion disk and use tomography to model the geometry of the disk during its precession.

Research: Published work

ORCID logo https://orcid.org/0000-0002-4024-6967

First Author Publications

Brumback, M.C., Hickox, R.C., Bachetti, M., Ballhausen, R. Fürst, F.S., Pike, S., Pottschmidt, K., Tomsick, J.A., Wilms, J. 2018. ApJL, 861, L7.
"Discovery of pulsation dropout and turn-on during the high state of the accreting X-ray pulsar LMC X-4"

Brumback, M.C., Hickox, R.C., Fürst, F.S., Pottschmidt, K., Hemphill, P., Tomsick, J.A., Wilms, J., Ballhausen, R. 2018. ApJ, 852, 132.
"A possible phase dependent absorption feature in the transient X-ray pulsar SAX J2103.5+4545."

Contributing Author Publications

Bachetti, M., Maccarone, T.J., Brightman, M., Brumback, M.C., Fürst, F.S., Harrison, F.A., Heida, M., Israel, G.L., Middleton, M.J., Tomsick, J.A., Webb, N.A., Walton, D.J. Submitted to ApJ, 2019.
"All at once: transient pulsations, spin down and a glitch from the Pulsating Ultraluminous X-ray Source M82 X-2 "

Pike, S.N., Harrison, F.A., Bachetti, M., Brumback, M.C., Fürst, F.S., Madsen, K.K., Pottschmidt, K., Tomsick, J.A., and Wilms, J. 2018. ApJ, 875, 144.
"Observing the transient pulsations of SMC X-1 with NuSTAR"

Research: Conferences and presented work

European Week of Astronomy and Space Sciences, 2019, Lyon, France. Talk title: "What can neutron star X-ray binaries tell us about ultra-luminous X-ray pulsars?"

AAS HEAD Meeting, 2019, Monterey, Ca. ( see Poster )

Are AGN Special? The environmental dependence and global impact of AGN activity, 2018, Durham University, Durham, UK (see Poster)

ULX Pulsar Workshop, June 2018, ESAC, Madrid, Spain. Talk title: "Pulse dropout in LMC X-4: Bridging the gap between accretion properties in Eddington and super-Eddington pulsars"

NERQUAM #28, 2018, Yale University University. Talk title: "Discovery of pulsation dropout and turn-on during the high state of the accreting X-ray pulsar LMC X-4"

AAS HEAD Meeting, 2017, Sun Valley, Id. (see Poster)

NuSTAR Science Meeting, 2016, Pasadena, Ca. (see Poster)

Hidden Monsters: Obscured AGN and Connections to Galaxy Evolution Workshop, 2016, Dartmouth College (Attended)

AAS HEAD Meeting, 2016, Naples, Fl. (see Poster)

NERQUAM #26, 2016, Brandeis University. Talk title: "Exploring the warped accretion disk around the magnetized neutron star LMC X-4"

NERQUAM #25, 2015, Dartmouth College (Attended)

Read my full CV here.


Getting others interested in astronomy is one of the most rewarding parts of my job.

Undergraduate Courses

I enjoy being a teaching assistant to undergraduate courses in astronomy and physics. The duties of a teaching assistant include holding regular office hours, conducting laboratory experiments, and grading assignments. I have been a TA for Understanding the Universe (Physics 1 and 2), General Physics I and II (Physics 3 and 4), as well as Exploring the Solar System (Astronomy 1) and Exploring the Universe (Astronomy 2 and 3).


I participate in a number of outreach events in the Upper Valley. Along with other astronomy graduate students, I host Public Observing at Dartmouth. I also attend the Montshire Museum of Science's anual Astronomy Day as a guest astronomer. I have also spoken at high schools throughout New England on topics from galaxy evolution to the search for extraterrestrial life.

Classroom Experience

As part of my Education minor at Hamilton College, I completed over 100 hours of classroom teaching at Clinton Middle School. I wrote and delivered lessons focusing on Newton's Laws to the seventh grade science class. I enjoyed including exciting demonstrations, such as the bed of nails (shown above) and the rocket bike, in my lessons.

About Me

While research can be time consuming, I enjoy a number of hobbies outside of the office.


Some of my favorite things about living in New Hampshire are the winter sports. I am an avid downhill skier and an aspiring ice hockey player. I currently play for the Physics and Astronomy intramural hockey team, the Absolute Zeros. Above is a photo of me scoring a goal for our team!


In the warmer months, I enjoy hiking and kayaking around the Upper Valley. When I'm not outside, I enjoy playing board games with friends, drawing, and reading. Currently, my favorite authors are P. Rothfuss, H. Murakami, B. Sanderson, and M. Crichton.


I attended Hamilton College, where I majored in Physics and minored in Mathematics and Education. I graduated Summa Cum Laude in 2014. Click below to view my complete CV.