Editor’s Note: Dr. Sulentic will in Mexico City and Baja, California, from Oct. 8-16. He will be checking e-mail daily and looks forward to talking to the media about this subject. On Oct. 8 and 9 he can be reached at the Institute of Astronomy, UNAM, Mexico City, 525/622-3908 or 525/616-1312 as the guest of Dr. Margarita Rosado. After that, e-mail is the best means of contact.

NGC4319 and Markarian 205

TUSCALOOSA, Ala. - Dr. Jack Sulentic, a professor of astronomy at The University of Alabama, says a release from the Hubble Heritage incorrectly reports that there is no bridge between the famous galaxy-quasar pair NGC4319-Markarian 205.

Hubble (Space Telescope) Heritage is an organization connected with the Space Telescope Science Institute, and made its release on Oct. 3 http://oposite.stsci.edu/pubinfo/
PR/2002/23/index.html.

In 1983, Sulentic reported that both NGC4319 and Markarian 205 were connected, which supported a claim presented in 1972 by astronomer H.C. Arp at the Max Planck Institut fur Astrophysik, Munich, Germany.

At the time Sulentic said that “during the past 10 years, many astronomers have argued that Arp’s data had to be either incorrect or due to something other than a physical connection, since the redshift-implied distances of both objects are significantly different.”

Through image enhancement and analysis, Sulentic directly confirmed Arp’s findings of a luminous connection between the two. His evidence was based on processing Arp’s Palomar and Kitt Peak telescope images.

Sulentic performed his study at the Jet Propulsion Laboratory in Pasadena, Calif., during a 1982 NASA summer faculty fellowship.

At the time two alternate explanations for the connection had been proposed: a foreground star or background galaxy located between galaxy NGC4319 and the Markarian 205 quasar giving the appearance of a connection or, the fuzzy edges of the two objects overlap when viewed through the telescopes.

Sulentic analyzed the light distribution in the area between the quasar and the galaxy and showed mathematically that neither theory was possible.

He stands by his finding. “The release tells us that the most recent Hubble Space Telescope images of this system do not show a connection. The papers H. Arp and I wrote have never been refuted in scientific literature. Did we make a mistake no one told us about?”

He says that a quick glance at the HST composite image reveals that the image of the galaxy-quasar pair is presented in a way that emphasizes the brightest parts of the galaxy and the quasar so that the impression is given that there is no light between the two objects.

“Our work showed that the connection was of low surface brightness,” he says. “In order to see it one would have to “burn out” the bright parts of the image and emphasize the fainter light levels. Technically speaking, the dynamic range in the image is so great that one cannot see all light levels at the same time.”

However, he says the Hubble picture actually does show the luminous connection on the web image by increasing the contrast at fainter levels.

“You can see the narrow core in the connection, which HST is able to detect because of its excellent resolution,” Sulentic says. “It is seen exactly where we found it in the earlier studies. Using the HST Heritage web data one can quickly show different versions of the image where the connection is visible. The pictures shown here clearly reveal the connection at low surface brightness levels that should enable readers to form their own judgment. Hubble Space Telescope has in fact, confirmed the earlier work.”

He says there are two independent questions on this issue. The first is does a luminous connection exist? And secondly, if a connection exists, what does it mean? Sulentic says the answer to the first question is yes.

But that opens the possibility, however remote, that the redshift of at least one of these objects is not telling us the correct distance (Quasars, Redshifts and Controversies H. Arp).

“There may be other less controversial interpretations as well, but even the possibility of the former may be inadmissible to some astronomers,” he says.

Sulentic teaches in the department of physics and astronomy in the College of Arts and Sciences. The College of Arts and Sciences is UA’s largest division and the largest public liberal arts college in the state, with approximately 5,000 undergraduate and 1,000 graduate students. The College has received national recognition for academic excellence, and A&S students have been selected for many of the nation’s top academic honors, including 15 Rhodes Scholarships, 13 Goldwater Scholarships, seven Truman Scholarships and 11 memberships on USA Today’s Academic All-American teams.