TY - JOUR
T1 - Calibration of AGN Reverberation Distance Measurements
AU - Koshida, Shintaro
AU - Yoshii, Yuzuru
AU - Kobayashi, Yukiyasu
AU - Minezaki, Takeo
AU - Enya, Keigo
AU - Suganuma, Masahiro
AU - Tomita, Hiroyuki
AU - Aoki, Tsutomu
AU - Peterson, Bruce A.
PY - 2017/6/20
Y1 - 2017/6/20
N2 - In Yoshii et al., we described a new method for measuring extragalactic distances based on dust reverberation in active galactic nuclei (AGNs), and we validated our new method with Cepheid variable stars. In this Letter, we validate our new method with Type Ia supernovae (SNe Ia) that occurred in two of the AGN host galaxies during our AGN monitoring program: SN 2004bd in NGC 3786 and SN 2008ec in NGC 7469. Their multicolor light curves were observed and analyzed using two widely accepted methods for measuring SN distances, and the distance moduli derived are m = 33.47 ± 0.15 for SN 2004bd and 33.83±0.07 for SN 2008ec. These results are used to obtain independently the distance measurement calibration factor, g. The g value obtained from the SN Ia discussed in this Letter is gSN = 10.61 ± 0.50, which matches, within the range of 1? uncertainty, gDUST = 10.60, previously calculated ab initio in Yoshii et al. Having validated our new method for measuring extragalactic distances, we use our new method to calibrate reverberation distances derived from variations of H? emission in the AGN broad-line region, extending the Hubble diagram to z " 0.3 where distinguishing between cosmologies is becoming possible.
AB - In Yoshii et al., we described a new method for measuring extragalactic distances based on dust reverberation in active galactic nuclei (AGNs), and we validated our new method with Cepheid variable stars. In this Letter, we validate our new method with Type Ia supernovae (SNe Ia) that occurred in two of the AGN host galaxies during our AGN monitoring program: SN 2004bd in NGC 3786 and SN 2008ec in NGC 7469. Their multicolor light curves were observed and analyzed using two widely accepted methods for measuring SN distances, and the distance moduli derived are m = 33.47 ± 0.15 for SN 2004bd and 33.83±0.07 for SN 2008ec. These results are used to obtain independently the distance measurement calibration factor, g. The g value obtained from the SN Ia discussed in this Letter is gSN = 10.61 ± 0.50, which matches, within the range of 1? uncertainty, gDUST = 10.60, previously calculated ab initio in Yoshii et al. Having validated our new method for measuring extragalactic distances, we use our new method to calibrate reverberation distances derived from variations of H? emission in the AGN broad-line region, extending the Hubble diagram to z " 0.3 where distinguishing between cosmologies is becoming possible.
KW - Galaxies: distances and redshifts
KW - Galaxies: individual (NGC 3786
KW - NGC 7469)
KW - SN 2008ec)
KW - Supernovae: individual (SN 2004bd
KW - cosmological parameters
UR - http://www.scopus.com/inward/record.url?scp=85021205874&partnerID=8YFLogxK
U2 - 10.3847/2041-8213/aa7553
DO - 10.3847/2041-8213/aa7553
M3 - Article
SN - 2041-8205
VL - 842
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L13
ER -