Photo in Inyo NF

Benjamin Weiner

Steward Observatory, Department of Astronomy, University of Arizona

About me: I am an Assistant Staff Scientist at the MMT Observatory and Associate Astronomer at Steward Observatory. At MMT, I work on supporting and developing instrumentation, observing, and telescope capabilities, and supporting data handling and reduction, with an emphasis on our spectroscopic instruments. Previously at Steward, I have worked on the MIPS team, on optical and infrared observed programs from the ground and with the Hubble and Herschel satellites, and on creating a network and modern observing system for Arizona's medium-size telescopes. MIPS was the far-infrared instrument on the Spitzer satellite. Prior to moving to Arizona, I was at Maryland working on the Maryland-Magellan Tunable Filter (MMTF) with Prof. Sylvain Veilleux.

I am PI of the AGHAST infrared grism spectroscopic survey, a survey of the GOODS-N field using an infrared grism in HST's WFC3-IR. I have been heavily involved in the CANDELS HST survey, a multi-cycle Treasury program using HST's WFC3-IR to do imaging (and a little spectroscopy) of five deep fields to study distant galaxies: our goals include obtaining deep infrared images to detect high-z galaxies, measuring galaxy masses, restframe optical sizes, colors, and morphologies, and discovering distant supernovae.

The Past: I returned to the North American tectonic plate in 2004 after several years on the Pacific plate - I was a postdoc with the DEEP project at UCO/Lick Observatory at the University of California, Santa Cruz and a Carnegie Fellow at the Carnegie Observatories. I studied for a PhD in physics at Rutgers University, alma mater of Mr. Magoo, and went to Swarthmore College as an undergrad. I was born in California (that makes me a citizen, so they can't kick me out if they secede) but grew up in Pittsburgh. Link for more tedious biographical details.

NGC 1365 velocity field image Some Science: The velocity field of the galaxy NGC 1365, observed with the Rutgers Fabry-Perot, at the CTIO 1.5-m telescope, the instrument my advisor built and that I used for my thesis. This velocity field was analyzed in Zanmar Sanchez, Sellwood, Weiner, & Williams (2008) ApJ, 694, 797.

MMT Observatory Resources

  • MMT Observatory
  • Hectospec spectrograph
  • Hectospec observers manual
  • Binospec spectrograph technical info at CfA (not up to date)
  • Binospec information for MMT users (up to date version of preliminary page below)
  • Read this: Preliminary information for Binospec observers - updated after commissioning and first science semesters
  • Frequently asked questions about using Binospec
  • Presentation summary of spectroscopy at MMT Binospec and Hectospec, how to choose, etc
  • Spectrophotometric Standard Stars with Proper Motions - an update of the "ESO spectrophotometric standards" list with Gaia positions and proper motions, updated to epoch 2015.5. Important to find stars if your instrument sets to absolute coordinates, like Binospec, or has a narrow field of view.
  • Properties of the CCD detectors for MMT Blue and Red Channel spectrographs
  • Some information and tips I have compiled on Hectospec data reduction and fixing problems.

    Professional Stuff

    Steward / NOAO Galaxy Group Lunch Talk Schedule

    My CV as of March 2023
    A description of some of my research interests
    ADS query for my publications, or my peer-reviewed publications

    Astronomy: instruments, teaching material

    An introduction to scaling relations for instruments for large telescopes.

    This is a brief tutorial essay intended to go over some simple optics governing instrumentation for astronomical telescopes, including simplified reimaging cameras and spectrographs. The original motivation for this essay was to provide a non-specialized answer to the question: "Why do instruments for large telescopes have to be large?"

    The tutorial covers only basic, idealized material that astronomers should know but is paradoxically a bit too basic or astronomy-specific to learn from an optics text (no actual lens design, aberrations, and so on). It may be useful for people taking or teaching a class in observational techniques. You can read the essay in HTML form or follow the link within for a PDF to print.

    Data downloads and releases

    -- Data tables for Template Spectra for Infrared-Luminous Galaxies from G.H. Rieke et al 2009, ApJ 692, 556.

    -- Digital versions (FITS files) of the model gas density and velocity field in the Milky Way bar, from B.Weiner and J.Sellwood 1999, ApJ, 524, 112. This is old stuff but still useful when trying to interpret velocities and distances of objects in the inner Milky Way.

    -- Machine readable tables for the DEEP1 redshift survey catalog (Weiner et al 2005) and the TKRS galaxy kinematics sample (Weiner et al 2006a) should be freely downloadable from either the ApJ web site or (use retrieve source option).

    -- If there's an image, data table, simulation model, and so on from one of my papers or projects that you need in digital form, please email me. Even if it's old. I try to keep these things available for archival purposes.


    Some possibly useful astronomical software that I've written. Includes a reduction pipeline for the Large Binocular Camera (LBC) on the Large Binocular Telescope (LBT). Also has some links to not-useful polemics.

    NEW for 2012: On the useful software page I now have a PGPLOT for Mac OS X set of config files and installation instructions that will work on Mas OS X 10.6 and 64-bit machines, which has been a nuisance for a lot of people.

    "Astronomical Software Wants to be Free," a white paper on the role of astronomical software and its authors submitted to the Astro 2010 Decadal Survey call for papers on the State of the Profession.

    My talk on code release titled, "Occupy Hard Drives: Making your work more valuable by giving it away," delivered at a special session of the January 2014 meeting of the AAS (American Astronomical Society). The session was organized by Alice Allen of the Astrophysics Source Code Library; visit for a detailed summary and links to the talks. My takeaway sentence is: I argue that writing, freely releasing, and publishing your software is currently not adequately funded, rewarded, or credited, and that you should do it anyway.

    Research interests

    This area under construction/to be expanded:

    - Indicators of star formation and extinction from UV, optical emission line, and infrared measurements
    - Gaseous outflows from galaxies, and their link to QSO absorpion line systems, accretion, and the cycling of baryons between galaxies and the circumgalactic medium
    - Kinematics of galaxies to z=1 and evolution in the Tully-Fisher relation
    - Study of galaxy formation and evolution through measurements of galaxy structure (luminosity, color, concentration, bulge/disk) and internal kinematics (velocity widths, rotation, non-circular motions) from local galaxies to z=1
    - Structure, dynamics and evolution of barred galaxies
    - Faint optical emission from high-velocity clouds
    - 2-dimensional spatially resolved spectroscopy: Fabry-Perot and integral field
    - Computational fluid dynamics, simulations of gas flow in galaxies
    - Optical telescope instrumentation


    Is there a proposal submission order effect? Does getting a low or high proposal number affect your chances of acceptance, for example due to TAC fatigue? For Spitzer proposals at least, the answer appears to be no, and we can prove it with SCIENCE.

    Three Maxims for Astronomical Projects:

    Weiner's First Rule of Instrumentation:

    No electrical problem is so mysterious that it cannot be explained by a bad connector.

    Weiner's Statistical Test:

    Never trust a statistician who is reluctant to utter the words "I don't know."

    A Programmer's Caution:

    Version control isn't any help if all the versions stink.

    Contact information

    Benjamin Weiner
    Steward Observatory
    University of Arizona
    933 N. Cherry St.
    Tucson, AZ  85721
    email: bjw -at-
    phone: 520-626-3508

    Unprofessional Stuff

    Some older photographs.

    Reasons to go to the telescope:

    Number 1
    Number 2

    Bored with the web?

    Here are some links to places slightly better than this modest (i.e. lame) page.

    Museum of Jurassic Technology
    Source Sriracha: Huy Fong Foods
    Iron Chef [unofficial]
    The Quincy, M.E. Punk Rock Episode The original link is dead; the Request Line zine died some time ago and now the archive is gone too. And the link used to take you to Sam Goody, yet another example of why the web just isn't that interesting any more. What good is a medium that has no place for a tribute to a TV show in which Jack Klugman warns the nation of the dangers of punk rock? But wait, great news! Thanks to the Internet Archive, now you can still visit the all-powerful Quincy, M.E. Punk Rock Episode!


    The Four Steps to Project Completion:

    1. Concept
    2. Design
    3. Execution
    4. Blaming of the Uninvolved

    P.S. Are you ready in the event of a national emergency?