Welcome to the webpage of Dr. Christopher Russell

NASA Postdoctoral Program (NPP) Fellow

X-ray Astrophysics Laboratory, Code 662
Goddard Space Flight Center
Greenbelt, MD 20771

email: christopher.m.{last name}@nasa.gov
(obfuscated to avoid spam)

My Bio in the Goddard directory


Last Updated: Aug 1, 2017


Grants

Chandra Theory, Cycle 18 (here or here)
3D Hydrodynamic & Radiative Transfer Models of HETG Line Profiles from Colliding Winds
PI: C. M. P. Russell
Co-Is: K. Hamaguchi, M. F. Corcoran, T. I. Madura, S. P. Owocki, & T. R. Kallman


360-degree video

Update: Here is a link to the conference proceedings paper describing this work: arXiv:1707.06954

Inspired by the VR-goggle demonstration by Chi-Kwan Chan (Univ. Arizona) at IAU Symposium 322, I created my own 360-degree video content (the more appropriate term is "4pi-steradian video," but I guess we'll let that slide) of the Galactic Center and massive-star binaries.

The best way I have found to distribute these video so far is with YouTube since they have a simple interface to view the content in its 360-degree form. On a computer, simply use the directional pad that appears in the video to pan left, right, up or down. On a smartphone (better than a computer), open the video in the YouTube app and move the phone all around to pan, ala Google Sky. Best yet is to use VR goggles (e.g. Google Cardboard or Samsung VR, which is what I use) to get the full effect.


Here is the link to my YouTube channel with these 360-degree videos, which were first made public at IAU Symposium 329, aka NZStars2016.
tinyurl.com/cmpr360video

Alternatively, open the YouTube app in your smartphone and search for "Christopher Russell astronomy." The icon for my channel is me in a yellow shirt.

Here is a direct link to my favorite video so far, which shows a Galactic Center simulation of the 30 Wolf-Rayet stars and their winds orbiting Sgr A* (simulation by Jorge Cuadra, Pontificia Universidad Católica de Chile) from the perspective of Sgr A*, i.e. the center of the simulation domain.
https://youtu.be/pK59iu4cNRM


Recent Papers, Talks, and Posters

(chronological order)

Invited Talk at Varibale Galactic Gamma-ray Sources IV

Here is the talk I gave in Tokyo, Japan, on July 6, 2017. It is on the pulsar+Be-star binary PSR B1259 and eta Carinae, and has the title Dynamically modeling non-gamma-ray observables of gamma-ray-emitting binaries.
Tokyo talk in pptx format

Talk at the workshop Eta Carinae, LBVs, and Supernova Impostors

Here is the talk I gave in Pittsburgh, PA, on June 23, 2017. It is on eta Carinae and the Galactic center, and has the title 3D modeling of massive interacting winds.
Pittsburgh talk in pptx format

Recent Paper

Here is a link to the paper:
Modelling the thermal X-ray emission around the Galactic Centre from colliding Wolf-Rayet winds
Russell, CMP; Wang, QD; & Cuadra, J, 2017, MNRAS, 464, 4958
It is available on the MNRAS website and on astro-ph.
http://adsabs.harvard.edu/abs/2017MNRAS.464.4958R

IAU 322 Symposium: The Multi-Messenger Astrophysics of the Galactic Centre

Here is the talk I presented at this Galactic center meeting on July 18, 2016 in Cairns, Australia.
Title: Modeling Diffuse Emission around the Galactic Center from Colliding Stellar Winds
IAU 322 Talk, pptx version (with movies) (If the movies do not play, please let me know.)
IAU 322 Talk, pdf version (no movies)

HEAD 2016 Poster

Here is the poster I presented at the 2016 meeting of the High Energy Astrophysics Division (HEAD) of the American Astronomical Society (AAS) in April in Naples, FL.
Session: Galactic Black Holes
Title: Modeling the thermal X-ray emission around the Galactic Center from colliding Wolf-Rayet winds
HEAD poster

Recent Paper

Here is a link to the paper Modelling the Central Constant Emission X-ray component in eta Carinae. It is available on the MNRAS website, on astro-ph, and was be officially published in May, 2016.
http://adsabs.harvard.edu/abs/2016MNRAS.458.2275R

AAS 2016 Presentation

Here is the presentation (Powerpoint, .pptx) I gave at the American Astronomical Society (AAS) 2016 meeting on Jan 8 in Kissimmee, FL.
Session: The Milk Way, Galactic Center
Title: Modeling Diffuse X-ray Emission around the Galactic Center from Colliding Stellar Winds
AAS presentation
(If the movies do not play, please let me know.)



Ongoing work

(intended mostly for collaborators)

SPH sims of more than 2 stars

With the anticipation of studying triple+ systems, I added the capability of modeling any number of point masses (object ejecting winds and have a gravitational inlfuence, or objects that just have a gravitational influence) to the SPH code.
Here is the test problem I did, a double eta Car. I added in another primary and secondary, flipping the coordinates and velocities (x --> -x) so they start aligned. The evolution of the systems is pretty cool, as shown by these movies on the properties of the orbital plane:
Density
Temperature
Velocity

eta Car: reanalyzing RXTE flux and varying secondary wind parameters

See here for some work on eta Car.

Opacity for driving stellar winds in SPH

See here for some work on how we implemented the opacity to radiatively drive the winds from their surface in the SPH simulations

CAK in SPH

See here for some work about implementing CAK theory (after Castor, Abbott, and Klein 1975 and much work thereafter) to drive the stellar winds in our hydrodynamic simulations.

HD 5980

See here for older hydrodynamic simulations of the colliding winds in the LBV+WR system HD 5980.

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