In the tradition of "Friday Cat Blogging" (in which I will doubtlessly indulge at some point, what with being a nutty cat person), I intend to establish my own tradition of putting up some pretty picture or another of a galaxy each Friday. Today is barred spiral galaxy NGC 1365.
The spiral arms in this galaxy are apparent, as is the bar; this is one of the classic examples of a barred spiral galaxy. It was also the subject of a poster presented a month and a half ago at the AAS meeting in Seattle by my grad student, Katie Chynoweth. These images were taken by me with the 1.0m SMARTS telescope at Cerro-Tololo Inter-American Observatory (CTIO) in Chile. The color image combines images through a blue, green, and red filter, each of which had something like 1/2 hour of total integration time.
We're looking at NGC 1365 because it's a member of what's called the "Bright Galaxy Sample." That doesn't mean exactly what it sounds; it should really be called the "IRAS Bright Galaxy Sample," as it is a set of galaxies that are particularly bright in the infrared region of the spectrum; IRAS was an infrared satellite from a couple of deacdes ago. This galaxy is luminous enough in the infrared to qualify as a "LIRG" or "Luminous InfraRed Galaxy". These galaxies all have a huge amount of star formation. The star formation tends to be embedded in dense, dusty molecular clouds. The light from the star formation is partially trapped in the dust, heating it up; the dust radiates then in the infrared, making these galaxies LIRGs. This galaxy also has an active galacitc nucleus.