Telescopes I've Used - ARC 3.5m

3.5m telescope, Astrophysical Research Consortium, Apache Point, New Mexico

ARC 3.5-meter enclosure ARC 3.5m telescope

The Apache Point Observatory, located in the Sacramento Mountains of New Mexico just south of the Sacramento Peak solar observatory, was among the first of the wave of university consortia building their own telescopes, partly in reaction to limitations in the availability of national facilities. The 3.5-meter telescope incorporated such features as a compact housing, altazimuth mount, and air piping to improve the seeing. The site is shared with the 2.5m survey telescope and 50-cm calibration telescope of the Sloan Digital Sky Survey, and the 1.0-meter telescope of New Mexico State University, which is the closest of the operating partners in the Astrophysical Research Consortium. One of the most noteworthy results from the 3.5-meter has been in followup of interesting objects, such as high-redshifts QSOs, found by the Sloan survey.

In a project with Frazer Owen and Mike Ledlow, I've used data from the double spectrograph and near-IR camera at the 3.5-meter to examine the oddball radio galaxy 0313-192 in the cluster Abell 428. It's clearly a classical double radio source, but the host galaxy, bucking an almost unbroken trend, looks like a spiral. It's almost edge-on, has a distinct bulge and disk, and shows pretty convincing evidence of spiral arms in our best images. How does a spiral do this, and why this one when we know of no other convincing examples? We're happy enough to speculate... Here are some APO data on the object, taken from the figures we put in the formal paper. First is a B-band image shown in two contrast mappings, to show the inner structure plus evidence for tidal interaction with a companion galaxy. Then we compare the rotation curves as observed in H-alpha and the [O III] emission line simultaneously with the double spectrograph. The extent of emission and linear shape of the velocity-position relationship are typical of dusty spirals seen almost edge-on.

APO B image of 0313-192 APO rotation curves of 0313-192

You can see the site in this satellite image from Google Maps. Hunting to the northwest will show the solar facilities at Sacramento Peak.

2.5m telescope, Sloan Digital Sky Survey, Apache Point, New Mexico

SDSS 2.5-meter telescope Spectrotraphs
on SDSS 2.5m telescope

In a way, this is everybody's telescope. The 2.5m has been the centerpiece of the Sloan Digital Sky Survey (SDSS), producing public imaging and spectroscopic data covering over 1/4 of the celestial sphere with unprecedented depth and precision. It features a very wide field of view, alowing the imaging program to scan strips of sky 3 degrees wide and simialry for spectroscopy, locate optical fibers across this area at once. On an altazimuth mount, the telecope is protected by a slotted wind shield around its supporting structure. from a daytime visit in 2008, these pictures show the telescope in its rollaway housing, the twin spectrographs used in the galaxy and quasar surveys, and one of the metal plates into which the optical fibers were plugged for a specific field (shown by site director Bruce Gillespie). Among many other projects, data from the SDSS were the basis of the original Galaxy Zoo. I described a visit to Apache Point at greater length for the Galaxy Zoo blog.

Telescope Collection

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