“BC03”的版本间差异
无编辑摘要 |
无编辑摘要 |
||
| 第3行： | 第3行： | ||
:AIRTOVAC可转换 |
:AIRTOVAC可转换 |
||
*3323-9301是高分辨率，1A |
*3323-9301是高分辨率，1A |
||
* |
|||
*As noted by Asari et al. (2007), the Bruzual & Charlot (2003) models have a low amplitude hump in the ∼100 Å interval around |
*As noted by Asari et al. (2007), the Bruzual & Charlot (2003) models have a low amplitude hump in the ∼100 Å interval around |
||
Hβ, such that Hβ emission often sits in a slightly negative valley in the observed minus model spectrum (an artefact of the STELIB |
Hβ, such that Hβ emission often sits in a slightly negative valley in the observed minus model spectrum (an artefact of the STELIB |
||
library, which disappears when using models based on the MILES library of Sanchez-Bl ´ azquez et al. 2006). Asari et al. (2007) found ´ |
library, which disappears when using models based on the [[MILES]] library of Sanchez-Bl ´ azquez et al. 2006). Asari et al. (2007) found ´ |
||
this effect to be unimportant for their Hβ measurements, but their analysis focused on SF galaxies, which tend to have strong Hβ. Here |
this effect to be unimportant for their Hβ measurements, but their analysis focused on SF galaxies, which tend to have strong Hβ. Here |
||
it has a larger impact, since we are specifically interested in galaxies with intrinsically weak Hβ. To alleviate this problem, the Hβ flux |
it has a larger impact, since we are specifically interested in galaxies with intrinsically weak Hβ. To alleviate this problem, the Hβ flux |
||
2024年6月30日 (日) 08:47的版本
- AIR 波长，SDSS的谱是真空波长
- AIR = VAC / (1.0 + 2.735182E-4 + 131.4182 / VAC^2 + 2.76249E8 / VAC^4)
- AIRTOVAC可转换
- 3323-9301是高分辨率，1A
- As noted by Asari et al. (2007), the Bruzual & Charlot (2003) models have a low amplitude hump in the ∼100 Å interval around
Hβ, such that Hβ emission often sits in a slightly negative valley in the observed minus model spectrum (an artefact of the STELIB library, which disappears when using models based on the MILES library of Sanchez-Bl ´ azquez et al. 2006). Asari et al. (2007) found ´ this effect to be unimportant for their Hβ measurements, but their analysis focused on SF galaxies, which tend to have strong Hβ. Here it has a larger impact, since we are specifically interested in galaxies with intrinsically weak Hβ. To alleviate this problem, the Hβ flux measurements were performed with respect to a local ‘continuum’ in the residual spectrum. No such systematic residual is found for other emission lines, whose measurement does not require the extra care devoted to Hβ.