M33 0.75x0.75 deg combined 6cm+20cm (2018 March 04)

See the catalog description for details on the images and the catalog. There is a radio catalog (creating by doing source detection on the radio images) and also "forced photometry" catalogs for SNRs, HII regions, and X-ray sources (created by integrating the radio data over the elliptical or circular regions for the sources.)

The M33 image cutout server provides an easy way to examine the radio, H-alpha, X-ray, etc. images at a particular position or at a list of positions.

Display notes

• Recent changes: Overlays are available for radio, SNRs, HII regions and X-ray sources. Use +/- keys to zoom image. Zoom up to 5400 pixels (twice as big as the image) for higher resolution.
• You can change the Display size of the displayed image (2700 is full resolution with 1 arcsec pixels) either by clicking on the size buttons or by using the + and - keys. Click the Blink frames button to blink between images. It cycles through all the images that have the "Include in blink" column checked. The FITS links allow downloading the images (and note that there are links above for the catalog and the "island" maps that show the locations of sources). The Display link brings up the HLA interactive display, which allows panning, zooming, changing the contrast, and overlaying some external catalogs.
• Click boxes from the Overlays to show graphical overlays for the radio detection islands, Knox's SNR catalog, the Lin et al. (2017) HII region catalog, and the Tuellmann et al. (2011) X-ray catalog. The first row plots the actual boundaries of the islands, while the second row just plots (larger) circles at the source positions. You can toggle the visibility of these overlays using the keystroke commands r=Radio Islands, s=SNRs, h=HII regions, and x=X-ray sources. The correponding keystrokes for the catalogs are c, t, g, and y. You can also type b=blink to start or stop blinking. That makes it easy to turn them on and off even if you have scrolled down to the middle of the image and can't see the checkboxes.
• The radio islands show the regions used for radio source fitting. Red islands have source entries in the catalog; yellow islands either are too faint (less than 4-sigma) or failed in fitting, usually because the region was crowded.
• The DSS and Subaru images are matched optical images. There is clearly excellent agreement in the optical and radio morphologies for H II regions. I noticed one region southwest of the nucleus where there is a misaligned patch in the Subaru mosaic; in general the DSS astrometry is more trustworthy than the Subaru astrometry where they disagree.