**Biases in
Virial Black Hole Masses: An SDSS Perspective**

Shen, Yue; Greene, Jenny E.; Strauss, Michael A.; Richards, Gordon T.; Schneider,
Donald P. **2008, ApJ, 680, 169** (arXiv:0709.3098)

The full table 1 can be downloaded here.

The line flux and EW measurements for Hbeta, MgII and CIV are summarized in this fits table. Following is the description of the table. Note that the catalog and this fits table only contain objects with high S/N>6 within the line profile, which are recommended for statistical analyses on emission lines. Many lines with S/N<6 are in general measurable as the chi^2 fits can successfully converge; but the results are not to be trusted seriously and are likely biased. Nevertheless, in some cases you probably want to have as many measurements as possible, so I put an additional fits table here, which contains all measurable lines.

Tagname | Format | Description |

SDSS_NAME | STRING | SDSS DR5 designation |

PLATE | LONG | plate number |

FIBER | LONG | fiber number |

MJD | LONG | mjd number |

Z | DOUBLE | cataloged redshift |

HBETA_FE_NORM_FACTOR | DOUBLE Array[2] | normalization of iron template for Hbeta |

MGII_FE_NORM_FACTOR |
DOUBLE Array[2] | normalization of iron template for MgII |

HBETA_REDCHI2_2 | DOUBLE | reduced chi^2 for Hbeta line fit |

HBETA_LINEFLUX_BR | DOUBLE Array[2] | broad Hbeta line flux |

HBETA_LINEFLUX_NA | DOUBLE Array[2] | narrow Hbeta line flux |

HBETA_EW_BR | DOUBLE Array[2] | broad Hbeta line EW |

HBETA_EW_NA | DOUBLE Array[2] | narrow Hbeta line EW |

OIII4959_LINEFLUX | DOUBLE Array[2] | [OIII]4959 line flux |

OIII4959_EW | DOUBLE Array[2] | [OIII]4959 line EW |

OIII5007_LINEFLUX | DOUBLE Array[2] | [OIII]5007 line flux |

OIII5007_EW | DOUBLE Array[2] | [OIII]5007 line EW |

MGII_LINEFLUX_BR |
DOUBLE Array[2] | broad MgII line flux |

MGII_LINEFLUX_NA |
DOUBLE Array[2] | narrow MgII line flux |

MGII_EW_BR | DOUBLE Array[2] | broad MgII line EW |

MGII_EW_NA | DOUBLE Array[2] | narrow MgII line EW |

MGII_REDCHI2_2 | DOUBLE | reduced chi^2 for MgII line fit |

CIV_LINEFLUX | DOUBLE Array[2] | CIV line flux |

CIV_EW | DOUBLE Array[2] | CIV line EW |

CIV_REDCHI2_2 | DOUBLE | reduced chi^2 for CIV line fit |

**NOTES:**

1. Emission line+continuum+iron template fits are described in Shen et al. (2008).
**The fits are done in restframe**.

2. Iron emissions are modeled for Hbeta and MgII, **but not for CIV.**

3. For MgII, I recommend to use the sum of the broad and narrow component EWs
as the MgII line EWs, since subtraction of a narrow component of MgII is not
justified.

4. Each of the DOUBLE Array[2] contains the value and the fitting error. If
their values are 0 then the fit failed or it is outside spectral range.

5. I won't trust the fits too much when the line is colse to the SDSS spectral
edge. So make reasonable redshift cuts for the line under consideration.

6. There may still be serendipitous cases where the line flux or EW is clearly
wrong (i.e., due to incorrect iron subtraction or something else). But the fraction
of these cases is tiny, so you may just neglect these cases.