My scientific research focuses on fundamental questions of observational astrophysics and cosmology. What is the nature and distribution of dark and luminous matter in the Universe? What processes drive the formation and evolution of structure? How has the global expansion of the universe changed with time? We explore these questions through several lines of research, but especially through observations of galaxy clusters.
My graduate students have cataloged tens of thousands of galaxy clusters using data from the Sloan Digital Sky Survey. Cross-correlating these cluster locations with weak lensing shear maps, X-ray observations, and galaxy redshift surveys allows us to precisely determine the relation between cluster galaxies and the masses of their dark matter halos. Interpreting these observations is complex. As a result, we work closely with Professor Gus Evrard’s structure formation simulation group to help generate mock universes. ‘Observing’ these mocks exactly as we do the real universe gives us unique insights into the complex relationships between dark matter mass and observables like shear and galaxy velocity.
I also work on a team with a number of other Michigan Physics faculty on the Dark Energy Survey (DES). The DES team is constructing a large new camera for the 4m telescope at the Cerro Tololo Interamerican Observatory in Chile. DES optical observations will be used in conjunction with the South Pole Telescope (SPT) Sunyaev-Zeldovich imager to detect galaxy clusters at very high redshift over a 4000 square degree region of the southern sky. Observations will begin in 2012.
I am actively seeking undergraduate and graduate students to work on galaxy cluster analysis projects.
In addition to astrophysics research, I am heavily engaged in the teaching of physics and I maintain a parallel group of students involved in education activities. Since 2006, I have been teaching and developing a new “Physics for the Life Sciences” introductory sequence (Physics 135 and 235). Students have played an essential role in the development and teaching of this course and it has provided an excellent training ground for students interested in science education. I am writing a textbook for this course, which is expected to be published by Pearson in Summer 2013.
More recently, we have begun a project to adapt expert coaching software developed in the UM School of Public Health for physics education. We are developing a new tool called, ECoach, which will provide individualized coaching to students taking introductory physics courses and advice which is aware of each student’s individual background, goals, and current standing in the course. This project is supported by a Next Generation Learning Challenge grant from the Gates and Hewlett Foundations.
Undergraduate and graduate students interested in participating in education projects should feel free to contact me at any time. I am especially eager to work with students who intend to make teaching physics an important part of their professional lives.
The Sloan Digital Sky Survey
The Dark Energy Survey
The ECoach Project
Finding Fossil Groups: Optical Identification and Chandra Confirmation, (Miller, E., et al.), submitted to The Astrophysical Journal (2011).
Robust Optical Richness Estimation with Reduced Scatter, (Rykoff, E., et al.), submitted to The Astrophysical Journal (2011).
Intrinsic Alignment of Cluster Galaxies: the Redshift Evolution, (Hao, J., et al.), submitted to The Astrophysical Journal (2010).
Searching for Needles in Haystacks – Using the Fermi/GBM to find GRB g-rays with the Fermi/LAT Detector, (Akerlof, C., et al.), The Astrophysical Journal 726, 22. (2010).
A GMBCG Galaxy Cluster Catalog of 55,424 Rich Clusters from SDSS DR7, (Hao, J., et al.), The Astrophysical Journal: Supplement Series 191, 254 (2010).
Searching for Needles in Haystacks - Looking for GRB ?-rays with the Fermi/LAT Detector, (Akerlof, C., et al.), The Astrophysical Journal 725 L, 15 (2010).
The Swift/Fermi GRB 080928 from 1 eV to 150 keV, (Rossi, A., et al.), submitted to Astronomy and Astrophysics (2010).
Alignment of Brightest Cluster Galaxies with their Host Clusters, (Niederste-Ostholt, M., et al.), Monthly Notices of the Royal Astronomical Society 405, 2023 (2010).
The Exceptionally Luminous Type-Ia Supernova 2007IF, (Yuan, F., et al.), The Astrophysical Journal 715, 1338 (2010).
GRB 090902b: Afterglow Observations and Implications, (Pandey, S.B., et al.), The Astrophysical Journal 714, 799 (2009).
ARBORZ: Photometric Redshifts for Galaxies Using Boosted Decision Trees, (Gerdes, D., et al.), The Astrophysical Journal 715, 823 (2009).
Baryon Acoustic Oscillations in the Sloan Digital Sky Survey Data Release 7 Galaxy Sample, (Percival, W., et al.), Monthly Notices of the Royal Astronomical Society 401, 2148 (2009).
Cosmological Constraints from the Clustering of the Sloan Digital Sky Survey DR7 Luminous Red Galaxies, (Reid, B., et al.), Monthly Notices of the Royal Astronomical Society 404, 60. (2009).
Precision Measurements of the Cluster Red Sequence using an Error Corrected Gaussian Mixture Model, (Hao, J., et al.), The Astrophysical Journal 702, 745 (2009).
Looking into the Fireball: ROTSE-III and Swift Observations of Early GRB Afterglows, (Rykoff, E., et al.), The Astrophysical Journal 702, 489 (2009).
Cosmological Constraints from the SDSS maxBCG Cluster Catalog, (Rozo, E., et al.), The Astrophysical Journal 708, 645 (2009).