page_title: Hot, dust-obscured galaxy
hierarchical_section_title: Hot, dust-obscured galaxy
caption_attribution_description: English: This image is a portion of the all-sky survey from NASA's Wide-field Infrared Survey Explorer, or WISE. It highlights the first of about 1,000 "hot DOGs" found by the mission (magenta circle). Hot DOGs are hot dust-obscured galaxies and are among the most powerful galaxies known. Yellow circles are active supermassive black holes found by WISE, which are much more common. The panels at right show the "Hot DOG" as seen in the four individual infrared bands obtained by WISE. These images are at wavelengths from 5 to 30 times redder than what our eyes can see, with the shortest wavelengths at top, and longest at bottom. Dust affects shorter wavelengths more than longer wavelengths. These objects are so dusty that not only their visible light but also their shorter-wavelength infrared light is blocked, as evident by their apparent absence in the top two panels. Less than one in 100,000 WISE sources are similarly prominent only in the two longer-wavelength WISE infrared bands.
context_page_description: A hot, dust-obscured galaxy, or hot DOG, is a rare type of quasar. The central black hole of such a galaxy emits vast amounts of radiation which heats the infalling dust and gas, releasing infrared light at a rate about 1,000 times as much as the Milky Way, making these some of the most luminous galaxies in the universe. However, the density of the surrounding dust is so great that most of that light is obscured. Their average temperatures range from 60 to 120 K, significantly higher than an average galaxy's temperature of 30 to 40 K. They also appear to concentrate a much higher proportion of their galactic mass in the central black hole than is observed in normal galaxies.
  Researchers believe that hot DOGs may represent a phase of galactic evolution where the central black hole is capturing material at a rate faster than new stars are forming, yet the radiation pressure from that rapid absorption is pushing away much of that surrounding material. The black hole will eventually clear its area of influence of the excessive dust and gas, rendering it a regular, visible galaxy.
context_section_description: A hot, dust-obscured galaxy, or hot DOG, is a rare type of quasar. The central black hole of such a galaxy emits vast amounts of radiation which heats the infalling dust and gas, releasing infrared light at a rate about 1,000 times as much as the Milky Way, making these some of the most luminous galaxies in the universe. However, the density of the surrounding dust is so great that most of that light is obscured. Their average temperatures range from 60 to 120 K (−213 to −153 °C; −352 to −244 °F), significantly higher than an average galaxy's temperature of 30 to 40 K (−243 to −233 °C; −406 to −388 °F). They also appear to concentrate a much higher proportion of their galactic mass in the central black hole than is observed in normal galaxies.
  Researchers believe that hot DOGs may represent a phase of galactic evolution where the central black hole is capturing material at a rate faster than new stars are forming, yet the radiation pressure from that rapid absorption is pushing away much of that surrounding material. The black hole will eventually clear its area of influence of the excessive dust and gas, rendering it a regular, visible galaxy.
  These objects were first detected by the Wide-field Infrared Survey Explorer (WISE) in 2010, and only one out of every 3,000 quasars observed by WISE are of this type. Wu et al (2012) refer to these galaxies as "W1W2-dropouts" because they are faint or invisible in WISE's W1 (3.4 μm) and W2 (4.6 μm) detection bands.
caption: A hot, dust-obscured galaxy seen by WISE
exif: {"Image ImageWidth": "3000", "Image ImageLength": "2400", "Image BitsPerSample": "[8, 8, 8]", "Image Compression": "LZW", "Image PhotometricInterpretation": "2", "Image Orientation": "Horizontal (normal)", "Image SamplesPerPixel": "3", "Image XResolution": "300", "Image YResolution": "300", "Image PlanarConfiguration": "1", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS6 (Macintosh)", "Image DateTime": "2012:08:23 17:53:20", "Image ExifOffset": "256", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "394", "Thumbnail JPEGInterchangeFormatLength": "0", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3000", "EXIF ExifImageLength": "2400"}