アブストラクト：
"Arp 187 is one of the dying active galactic nuclei (AGN) candidates, whose AGN activity is currently decreasing in luminosity, and is a good laboratory to obtain the crucial information on the accretion disk physics and the lifetime of AGN. We investigate the observational signatures of AGN in Arp 187, which traces various physical scales from less than 0.1 pc to the nearly 10 kpc, to estimate the longterm luminosity change over 10^4 years. We perform the Cycle-3 ALMA band 4 observation as well as the archival VLA 5 and 8 GHz data, which reveal bimodal jet lobes with ~5 kpc size as well as the absence of the central radio-core. The optical spectrum obtained from the 6dF galaxy survey shows that Arp~187 hosts bright ~1 kpc size narrow line region, whose predicted AGN luminosity roughly 10^4 years ago is Lbol=2.0x10^45 erg/s. On the other hand, the current AGN activity estimated from their AGN torus emission gives the upper bound of Lbol < 2.2 x 10^43 erg/s that is by a factor of 100 times weaker than the AGN luminosity 10^4 years ago. In addition, the absence of the radio-core gives the strongest upper bound of the current AGN luminosity of Lbol < 8.0 x 10^40 erg/s. These results indicate that Arp~187 has experienced the drastic luminosity decline by a factor of ~10^4 fainter within ~10^{4} years. "