2. Review of the Current Program 2.1 Conclusions and recommendations from the previous External Review The full report of the previous External Review is given in Appendix Ij; a capsule summary is given here:
The lead conclusion was that “the Astronomy and Astrophysics Department at Santa Cruz is excellent, among the top programs in the nation. With timely action, it can stay there….We endorse the plan [presented for the next eight years].” The committee then went on to highlight the following issues:
1) Strategic issues of faculty renewal are the most important single factor in the long-term health of the UCSC Astronomy program.
2) The stated strategy of broadening the Department by “developing at the borders” with Physics and Earth and Planetary Sciences is good. It “achieves the dual effect of meeting the aspirations of the Astronomy program and using its international reputation…to foster the development of other Santa Cruz departments.”
3) However, observational astronomy is expanding into other wavelength regimes, and the “narrow path of optical astronomy alone [even with theory] is not enough to keep Santa Cruz in the top echelon.” Santa Cruz needs to position itself to exploit the wide-range of multi-wavelength instrumentation listed in the 2000 Astronomy Decadal Survey, but such expansion needs to be tempered with “continuing strength” in theorists, who “act as glue” to hold the Department together.
4) The Department’s proposal to addfour FTE over the next decade is adequate to address expansion needs, provided all retirements are also replaced.
5) The Department has experienced some recent disappointments in losing good faculty, hiring new faculty, and attracting high-quality graduate students. However, two recent faculty hires are very good. The faculty “has excellent taste and judgment in making new hires.”
6) Faculty salaries, housing, startup funds, and graduate student stipends are not competitive with leading institutions elsewhere.
7) Winning the Center for Adaptive Optics is a great coup. However, the Self-Study did not pay sufficient attention to maximizing the benefit for the local scientific program as a whole. What are the goals with regard to CfAO?
8) The range of courses offered in the undergraduate program is impressive. The Astronomy minor and the Physics/Astrophysics major are very good developments.
9) The time to PhD degree (median six years) is too long. UCSC should aim for five years instead of six or longer. The committee recommended that thesis committees be created at the Qualifying Exam to which thesis students would be required to report every six months.
10) The task of Department Chair is one that “no rational person would choose gladly.” The resources that the Chair has to solve basic Departmental problems are “extraordinarily small.” Chairs should not be expected to donate their stipends (~$7000) to fill out the Department budget, which has become normal. Administrative support is “slender,” and Department staffing is “about half the support the committee would expect for a group of this size to function well.”
As the following report makes clear, progress has occurred on many of these issues, but several serious items still remain open.
2.2 Department vision Given the preponderance of faculty on the Observatory side (currently 15 out of 23 FTE), the core of our research expertise is—and must remain—in optical/infrared observational astronomy. This is mandated by UCO’s mission to provide optical/infrared facilities for the entire UC system. Our strategy has been to take this observational core and broaden it with theory, and the last Self-Study listed threeareas of scientific excellencein which we would attempt to build programs bridging both observations and theory. These areas are cosmology and galaxy formation, high-energy astrophysics, and star/planet/solar-system formation. Seven years later, these choices still look good—all three will certainly continue to be exciting research areas through at least the next decade, and all three fit well with the observational, laboratory, and computational facilities at our disposal.
However, our last Self-Study stressed that the science of astronomy is broadening, and excellent departments need to offer a wider research menu than in the past. The External Review committee agreed with this, and, indeed, the rather narrow research program at UCSC—theory plus optical-infrared observations—is the main reason given by recent graduate student applicants for not selecting UCSC. Our strategy since the last review has been to mount a top-flight program in observational optical/infrared astronomyand tobroaden this core through a tightly structured program based on theory plus other carefully selected wavelength regimes. We recently started a program in gamma-ray astronomy by collaborating with Physics, and opening a second such program, in long-wavelength astronomy, is a goal of the next review period.
Three strategies are open to adding the necessary expertise to broaden the program. One way is to partner with nearby astronomy institutions, a strategy pursued to great effect by other leading departments, such as Princeton with its nearby Institute for Advanced Studies and Plasma Physics Laboratory, UC Berkeley with the Space Science Laboratory and LBNL, Caltech with IPAC and the Jet Propulsion Laboratory, and Harvard with the Smithsonian Astrophysical Observatory. The importance of partner institutions to the success of other leading astronomy departments cannot be overstated. UCSC’s natural partners are NASA Ames, LBNL, and Lawrence Livermore National Laboratory, and we in fact have programs with all three. However, our relatively greater geographic isolation has kept these partnerships from flowering to the same extent. This option is not dead, but it is not easy.
A second way to broaden is by partnering with other UCSC departments, the strategy of “developing at the borders” articulated in the last Self-Study. We have made great progress on this during the review period and now have much closer ties with Physics, Earth and Planetary Sciences (EPS), and Applied Math and Statistics (AMS). These partnerships have brought new strength and vitality to our program and are referred to frequently in this Self-Study. However, Physics and AMS are extremely small departments compared to other leading departments in their fields,2 which severely limits both their national visibility and the number of faculty they can devote to astrophysics. The health of Physics is especially important, as the presence of a world-class astrophysics program in the neighboring Physics department is a ubiquitous feature of departments we wish to emulate.
The third and final way to broaden is by hiring new faculty within Astronomy. Studies have shown3 that scientific excellence strongly correlates with department size across all fields, and greater breadth is clearly the major reason. Our present allocation of 23 faculty FTE might seem large compared to UC Berkeley (17.5), Caltech (13), Harvard (17), and Princeton (16), but our effective faculty size is actually considerably smaller, for three reasons: (1) a large fraction of UCO faculty effort is directed to UC systemwide astronomy, which limits the time and attention they can spend on Department tasks, particularly on leadership roles; (2) two-thirds of the faculty are optical/infrared observers, leaving only eightto cover all of theory and all of multi-wavelength observations; and (3) of these eight, two are presently on leave in campus administration, leaving onlysix active at this time, which is actually one fewer than at the last review.4 We therefore believe that the Department size is too smallto mount a top-flight program covering all the necessary bases, and we propose again, as we did last time, to expand the faculty by adding four FTE. Two of these positions are already in the Division hiring plan (shown in Appendix Ih), and two would be new. The extra manpower would allow us to fill important gaps in the present theory program, as described below, and also expand into one more wavelength regime, which we believe should be some aspect of long-wavelength astronomy (i.e., far-infrared, submillimeter, and radio). Four major new telescopes will open soon at these wavelengths that will be vital for research in star, planet, and galaxy formation. Our programs in these areas will be seriously incomplete without the ability to utilize these forefront data.
The Department vision, then, remains essentially the same as what it was at the last External Review. We have made important progress towards many of the goals stated there, and the research program overall has become broader, stronger, and better integrated. However, the graduate and postdoctoral programs have emerged as needing attention, and the Department continues to suffer from lack of adequate resources. These points and others are discussed in more detail below.
2.3 Research, scholarship, and creative activity of the faculty 2.3.1 Highlights of the last review period: This section lists some notable achievements during the last review period, illustrating areas of recent scientific excellence.
The California-Carnegie Exoplanet team discovered the first sub-Saturn and Neptune-mass planets. Transit data were analyzed to discover a rocky core in the Saturn-mass companion to HD 149026, which provides a major clue to modes of giant- planet accretion. The high gravitational sensitivity of multi-planet systems was exploited to find the first very small planet, a 7.5 Earth-mass object orbiting GJ 876. Two team leaders are UCSC faculty (Vogt and Laughlin), and three have UCSC PhDs (Laughlin, Marcy, and Fischer). This team has discovered 65% of all ~200 exoplanets known.
Thorsett and collaborators confirmed a white dwarf companion to the pulsar B1620-26, which led to the discovery of the so-called “Methuselah planet” as a second orbiting companion.
More realistic models of giant-planet accretion by Bodenheimer and Fortney indicate that young jupiters will be 10-100 times fainter than previously thought. This has major implications for direct planet discovery programs.
Lin and collaborator Ida developed Lin’s now-classic planet-migration theory to predict where planets of various mass and composition will be found in extrasolar planetary systems. They suggested that the mass vs. orbital radius plot will become the “color-magnitude diagram” of planet formation, providing the standard test of new theories.
The Bay Area Computational Astrophysics Consortium led by Woosley won a $9.5 million DOE SciDAC grant to model supernovae and gamma-ray bursts. Meanwhile, Woosley’s “collapsar” model of black holes forming in the heart of supernovae explosions emerged as the leading candidate for long/soft gamma-ray bursts.
Ramirez-Ruiz and collaborators found that the temporal behavior of seemingly different kinds of gamma-ray burst afterglows are in fact all well described by relativistic blast-wave models.
Guhathakurta and collaborators found stars in our neighbor galaxy M31 (Andromeda) that extend to out half a million light years from the center. If we could see all of Andromeda with the naked eye, it would look twice as large as the Big Dipper.
The SAGES globular cluster survey led by Brodie and graduate student Jay Strader proved the existence once and for all of two populations of globular clusters—metal-poor ones formed in small proto-galaxies, and metal-rich ones formed later in the buildup of massive galaxies. Smith traced chemical inhomogeneities in globular cluster stars all the way down to the main sequence.
Rockosi was appointed PI of the SEGUE survey, a major follow-on to the Sloan Digital Sky Survey that will document the kinematic structure of our Galaxy. Two hundred forty thousand stellar spectra and radial velocities were collected and are being analyzed.
Max, Madau, and colleagues embarked on a study of black hole mergers in colliding galaxies; first results appeared as back-to-back papers in the June 29, 2007, issue of Science. Madau’s paper showed that the black holes from each merging galaxy form an eccentric binary in the central disk in less than 1 million years as a result of the gravitational drag from the gas rather than from the stars. Max’s paper used Keck adaptive optics to locate the exact positions of the two black holes in a pair of colliding galaxies and to characterize their position relative to the disks of gas and stars.
The Via Lactea N-body simulation by Madau and Hubble Fellow Juerg Diemand produced the highest-resolution N-body model yet of the gravitational formation of the Milky Way’s dark-matter halo. Ten thousand sub-halos down to 106 solar masses were identified, an order-of-magnitude more than in previous simulations.
Prochaska and graduate student Gabriel Prochter discovered four times more foreground galaxies toward gamma-ray bursts than toward quasars, a totally unexpected result that remains unexplained.
In the realm of distant galaxies, the ACS team on Hubble (Illingworth Co-PI) probed galaxy formation to unprecedented high redshifts and detected a large rise in the number of galaxies only 700 million years after the Big Bang. Faber, Guhathakurta, and Koo (with Davis from UCB) conducted the DEEP2 survey of 50,000 galaxies that probed 9 billion years back in time using the new DEIMOS spectrograph at Keck. DEEP2 spawned AEGIS, the most extensive multi-wavelength survey of galaxies thus far. First results from AEGIS were featured in the May 15, 2007, issue of Astrophysical Journal Letters and in the Hubble Review 2006 yearbook.
Educational programs and human resources:
The number of Astronomy graduate students increased from 26 to 38. Three Astronomy grads and two Physics grads won premiere Hubble Fellowships.
The Physics/Astrophysics undergraduate major grew from 10 to 51 students. Forty per cent of all Physics majors are now choosing the Astrophysics track.
CfAO launched instrumentation-training programs for both grads and undergrads.
The number of female faculty increased from two to four (and will grow further to five in 2007-8). We hired our first Hispanic faculty member. Female graduate students now comprise nearly half the grad student population.
CfAO Education and Human Resource program: Many faculty and two-thirds of all Astronomy graduate students participated in this program. The program has two thrusts: to help provide UCSC science and engineering graduate students with the teaching skills needed for their role as future faculty members, and to exercise these teaching skills in outreach activities aimed at local community-college science and engineering majors from under-represented groups. The program is widely acknowledged as one of the very top NSF STC education activities. Under current plans, a new UCSC-based “Institute for Scientist and Engineer Educators” (ISEE) will take over these activities in 2009. Outreach to minority-serving community colleges in Hawaii is planned to continue under external funding. Funds are being sought for outreach to local community colleges in the Santa Cruz-Watsonville-Salinas area, serving heavily Hispanic students.
Instrumentation and facilities:
Woosley led a partnership of faculty from Astronomy, Physics, EPS, and AMS that won a $1.1 M grant to bring UCSC’s first large mini-supercomputer to campus (Pleiades). Woosley, Madau (and Primack from Physics) were granted privileged early access to NASA Ames Columbia supercomputer, and Woosley and Madau were granted a total of 5.5 million CPU hours through DOE’s INCITE program.
Astronomy faculty advised on several space observatories. Thorsett was science chair for the Nuclear Spectroscopic Telescope Array satellite (NUSTAR, since cancelled) and is Interdisciplinary Scientist for GLAST. Illingworth is Co-PI for the Advanced Camera for Surveys on Hubble. Woosley is a science advisor on both HETE-2and NUSTAR. Lin served on the SIM and TPF-C science teams.
Highlights from the UCO and CfAO instrumentation labs: A new CCD mosaic detector (by Vogt) gave the HIRES spectrograph on Keck the highest UV efficiency of any high-resolution spectrograph in the world. The DEIMOS spectrograph (by Faber) propelled Keck to the forefront of multi-object optical spectroscopy. Vogt collaborated with Marcy at Berkeley to found the dedicated 2.4 m Automatic Planet Finder (APF) telescope on Mt. Hamilton. An outgrowth of CfAO was a $9 million gift to found the Gordon and Betty Moore Laboratory for Adaptive Optics on campus, which features the world’s most advanced laboratory equipment for testing AO instrumentation. LAO staff pioneered the first regular laser-guide-star AO system at Mt. Hamilton and assisted in installing a similar system at Keck. Nelson developed technology for the next round of giant ground-based optical telescopes, which spawned the Thirty-Meter Telescope project in collaboration with Caltech and Canada.
Leadership and service:
Lin was appointed founding director of the newest Kavli Institute, for Theoretical Astronomy and Astrophysics at Peking University.
Illingworth was founding chair of the Astronomy and Astrophysics Advisory Committee and guided that group to becoming one of the most respected astronomy advisory bodies in Washington.
Miller and Bolte served as directors of UCO, and Nelson and Max served as directors of CfAO. Guhathakurta served on the Science Advisory Panel for the Thirty-Meter Telescope, and Miller and Bolte served on the TMT Board of Directors and the CARA Board of Directors that oversees the Keck Observatory.
Faber served on the NRC panel recommending the Hubble refurbishment and on EPP2010, which recommended the International Linear Collider. Smith joined the editorial board of the Astronomical Society of the Pacific. Other faculty served on a wide variety of advisory committees for NASA, NSF, DOE, and public and private institutions.
Steve Thorsett serves as UCSC’s Dean of Physical and Biological Sciences, and Bruce Margon is Vice Chancellor for Research. George Blumenthal was Chair and Vice Chair of the UC systemwide Academic Senate for two years and stepped in last fall to become Interim UCSC Chancellor.
The above activities prompted considerable media coverage, including several articles on exoplanet discoveries by Vogt and Laughlin; press coverage on Hubble’s Advanced Camera for Surveys and its work; the DEEP2, AEGIS, and First Galaxies surveys; the size of M31’s halo; discoveries made with the Keck laser guide star AO system; and Prochaska’s gamma-ray galaxy counts, Woosley and Faber were filmed in two PBS documentaries.
Information on faculty interests is given in bios in Appendix Ia, including brief sketches for astrophysics faculty in other departments. This information is also summarized in Table 1, which tabulates faculty by scientific area. It is seen that coverage in all three chosen science excellence areas is fairly good, but strengths in theory vs. observation do not always match. For example, many of our optical-infrared observers work on galaxy evolution, but the corresponding number of theorists is small. A degree of mismatch between the research interests of observers and theorists is historical at UCSC, to the detriment of close collaborations. New faculty Fortney and Krumholz have interests that overlap those of many observers, and we expect that their coming will help to knit the two groups more closely together. An important goal of future hires is to further strengthen connections between observers and theorists. Table 1: Manpower distribution of astrophysics faculty by expertise and science area. Units are FTE. Includes administrators, recent hires, and affiliated faculty in other departments.
2.3.2 Measures of quality: The 1993 NRC survey of graduate departments rated UCSC Astronomy as number six in the country in terms of research excellence and number four in terms of graduate-training effectiveness. Details from this survey are presented in Appendices IVa1.D and IVa2.D. The next NRC rankings are not expected until Fall 2007. In the meantime, we believe that the most appropriate measure of faculty quality is citations per paper, commonly called the “impactfactor.” Table 2 presents a summary of six impact-factor studies of space science departments since 1995 based on the citations tabulated by the Institute for Scientific Information (ISI). Strikingly, only two institutions, Princeton and UCSC, appear as top-rated departments in all six studies, and their average positions are similar, with Princeton perhaps an eyelash ahead. We note that UCSC has achieved this level of excellence without the major institutional partnerships that other leading departments enjoy.The last line of Table 2 lists rankings for the UCSC Physics department, which emerged as #1 in impact factor among all US physics departments in the latest survey.
A second measure of quality is external awards and prizes. During the last review period, junior faculty Laughlin and Prochaska won NSF Career grants and Rockosi won a Packard Fellowship. Junior faculty Ramirez-Ruiz was appointed a lifetime Bahcall Fellow at the Institute for Advanced Studies. Woosley won the Bethe and Rossi Prizes of the American Physical and American Astronomical Societies. Miller was the fifth lifetime recipient of the UC President’s Certificate of Excellence in recognition of his outstanding service to the UC System as UCO director. He also received the Berkeley Medal, the highest award of UC Berkeley.5 Max received the Department of Energy’s E. O. Lawrence Award for her role in inventing laser-guide-star adaptive optics. Madau was an Alexander von Humboldt Fellow at the Max Planck Institute for Astrophysics in Garching. Faber received the Centennial Medal of the Faculty of Arts and Sciences of Harvard University and was elected to the Harvard Board of Overseers. Vogt was a World Technology Award Finalist for his achievement in astronomical spectrograph design and received both the Tinsley Prize and the Carl Sagan Memorial Award of the American Astronomical Society for his contributions to the California-Carnegie Exoplanet team.
Table 2: Rank order in terms of average citations per paper by leading astronomy departments, based on data in the Science Citation Index.
Max, Lin, Miller, and Woosley were elected to the American Academy of Arts and Sciences, bringing the UCSC Astronomy total to five. Woosley was elected to the National Academy of Sciences, bringing the UCSC Astronomy total to three. Faber was elected to the American Philosophical Society.
In sum, based on quantitative measures as well as peer recognition, UCSC astronomy faculty rank highly. Our junior faculty hired during the last review period—Laughlin, Prochaska, Rockosi, Ramirez-Ruiz, Fortney, and Krumholz—promise to maintain and even advance this standard of excellence.