Observed Spectral profile of M82
|Date & Time: ||Dec 24 2011, from 23:04 to 23:14 JST(+0900)
|Composed 2 shots with 10 minutes exposed|
|Optical: ||Meade 25cm(10") Schmidt Cassegrain (f=2500mm, F10.0)
|with SBIG DSS7 Spectrometer|
|Auto-guided with Meade LX200 Equatorial & Pictor 201 XT
|Cooled CCD Camera: ||SBIG ST-402ME (Temp.: -25°C)
|Location: ||Ooizumi, Hokuto city, Yamanashi pref.
Upper strip: taken spectrogram, Lower strip: stretched 3-pixel-width & pseudo-colored image
This page shows you the observed spectral profile of the central part of M82.
|Emission line||Hα||Hβ||S II|
|Observed WL, λm||6570 Å||4870 Å||6732 Å|
| WL in literature, λ0||6562.9 Å||4861.3 Å||6723.5 Å|
|Red shift, z||1.089×10-3||1.783×10-3||1.264×10-3|
|Recession velocity, v||326.7 km/s||534.6 km/s||379.0 km/s|
|Estimated distance, D||15.21 mill. lt-yr||24.89 mill. lt-yr||17.65 mill. lt-yr|
|(average)||17.65 mill. lt-yr|
D= 3.26*v/H0 (million lt-yr)
(c: velocity of light, H0=70 km/s/Mpc)
The profile shows clear emission line of the ionized nitrogen and sulfur atoms besides the Balmer series of H-alpha and H-beta.
A table in right has listed and indicated estimated distance to the galaxy from observed wavelengths.
The value can be calculated as about 17.6 million light years under an assumption that the Hubble constant of H0 has 70 km/s/Mpc.