2.1红外窗口 波段范围在0.7~1000微米之间 波长区间 波长范围（μm) 温度范围Kelvin) WHAT WE SEE Cooler red stars Near- (0.7-1)to5 740t0(3,000-5,200) Infrared Red giants Dust is transparent Mid- Planets,comets and asteroids 5t0(25-40) 92.5-140)to740 Infrared Dust warmed by starlight Protoplanetary disks Emission from cold dust Far- (25-40)t0(200- (10.6-18.5)t0(92.5- Infrared 350) 140) Central regions of galaxies Very cold molecular clouds Near-Infrared:0.7 to 2.5 um visible and infrared NASA/IPAC 93.4 Mid-Infrared:3 to 25 um 90 85 Far-Infrared:above 25 um. 75 73.6
2.1 /034 6@ABC0.7 ~ 1000DEFG visible and infrared 'I1a 'Icd(µm) ./cd(Kelvin) WHAT WE SEE NearInfrared (0.7-1) to 5 740 to (3,000-5,200) Cooler red stars Red giants Dust is transparent MidInfrared 5 to (25-40) (92.5-140) to 740 Planets, comets and asteroids Dust warmed by starlight Protoplanetary disks FarInfrared (25-40) to (200- 350) (10.6-18.5) to (92.5- 140) Emission from cold dust Central regions of galaxies Very cold molecular clouds Near-Infrared: 0.7 to 2.5 μm Mid-Infrared: 3 to 25 μm Far-Infrared:above 25 μm
2.2 Sources of IR Emission Dusty regions (i.e.star forming regions) Emission from warm dust (for typical temperature of galaxies,dust emission peaks ~100 um) Transparency of dust to IR radiation,longer wavelengths not scattered like visible radiation Keck Telescope Star-forming regions Visible PAHs Galaxies 10 100 1000 Infrared A/um Short-dashed:PAHs Spitzer Long-dashed:热尘埃辐射 Space Telescope Solid:温、冷尘埃辐射
2.2 Sources of IR Emission (I) u Dusty regions (i.e. star forming regions) u Emission from warm dust (for typical temperature of galaxies, dust emission peaks ~100 μm) u Transparency of dust to IR radiation, longer wavelengths not scattered like visible radiation M78 Short-dashedePAHs Long-dashedeUfg)* Solide.hifg)*
2.2 Sources of IR Emission ◆Cool objects small cool stars,red giants,brown dwarfs planets,comets,asteroids ASTERO0时 161K ◆ nebulae,interstellar dust,protoplanetary disks 1371W 12 MERCURY 591W ◆ Cool stars energy peak~lum 静w ◆ Dust re-radiation 20-200um SUN Sun Red hot Earth surface object surface 6000K 1800K 300K 4007001000nm 500 2500 4500 5101520 Wavelength 2 in nm Wavelength入inum 2+ Cosmic background radiation 2.7K 10152.02 Wavelength in mm Hubble infrared image of nearby star factory
2.2 Sources of IR Emission (II) u Cool objects u small cool stars, red giants, brown dwarfs u planets, comets, asteroids u nebulae, interstellar dust, protoplanetary disks u Cool stars energy peak ~ 1µm u Dust re-radiation ~ 20-200µm Hubble infrared image of nearby star factory
2.2 Sources of IR Emission (I High-redshift objects COSMIC EPOCHS Can select high-z galaxies based on breaks in the spectrum 1bn元t为m 。 Leading galaxies to appear in red bands but not bluer bands 4000A for z2,Lyman limit at 912 A z>7) 4.0 1 个 xnId Model galaxy at z=7.0 0.8 FUnattenuated Spectrum Z0=(83 0.6 3.0 0.4 Attenuated 0.2 Spectrum MOTTH Z=6.5 0 2.0 0.8 F606W F775W F850LP F110W F160W z=6.0 1.0 600 8001000120014001600 stars Wavelength (nm) 0.8 IRACnon-detection MACS0454-1251 平 MACS0454-1817 -0.5 0.0 0.5 1.0 1.5 2.0 F110W F160W
2.2 Sources of IR Emission (III) u High-redshift objects u Can select high-z galaxies based on breaks in the spectrum u Leading galaxies to appear in red bands but not bluer bands u 4000Å for z~2, Lyman limit at 912 Å z>7)
2.2 Sources of IR Emission (IV) High energy Molecular vibrational and rotational lines 5 Lines for CO,CO2,H2,H20,silicates Rotational levels Vibrational levels PAH features (polycyclic aromatic hydrocarbon) 。-Electronic levels Low energy Ground state (So PAH molecular structures and the PAH infrared signature. GL2591 silicate silicate H2O ice H2O ice 10 15 20 wavelength (microns) carbon dioxide (CO)ice 4.1 4.3 4.5 13 5 17 wavelength (microns) wavelength (microns)
2.2 Sources of IR Emission (IV) u Molecular vibrational and rotational lines u Lines for CO, CO2, H2, H2O, silicates u PAH features (polycyclic aromatic hydrocarbon) PAH molecular structures and the PAH infrared signature