After satisfactory completion of coursework, students must pass a Candidacy Exam in order to continue on for the Ph.D. In most cases, the Candidacy Exam is taken during the Summer term after the second year, after submission of one or more papers to refereed journals. The purpose of the Candidacy Exam is to test the student's understanding of basic astrophysics and depth of knowledge in his or her chosen research specialty.
Before beginning the exam, the student identifies a Candidacy Exam committee, consisting of four (4) Astronomy Department faculty. The Candidacy Examination Committee is chaired by the student's dissertation adviser. With the help of the Chair, the student selects a research field that will be the subject of the exam. The breadth of the field can vary, but it should be neither extremely narrow (e.g., relativistic aberration) nor overly broad (e.g., cosmology). The Candidacy Exam consists of a written (completed first) and an oral part, which is done after successful completion of the written part.
The written portion of the exam has three components. The first is a summary of 3 papers in the chosen research field. The second is an order-of-magnitude problem of the student's own devising, of comparable difficulty to the problems done in order-of-magnitude class. The third is a summary of the field as a whole. The student has 2 weeks to complete the written exam once assigned.
The oral exam is based upon a research project undertaken in the first 2 years of graduate school, and is scheduled within one month of the written portion of the exam. The oral exam consists of two parts. The first is an approximately 40 minute presentation to the exam committee on the completed research project. The second is an approximately 1 hour free-form question/answer session where the student may be asked about their presentation, their research project, or general astronomy and astrophysics.
For more details on the Candidacy Exam, please see the Astronomy Graduate Handbook.