azaryan's only stipulation on that sale, the dynamic duo's purchased as a pair.e >> they cannot be separated. they must stay together. they are the dynamic duo. can you imagine separating batman and robin? no way. they have to be together. >> reporter: as to why he is selling now -- >> it was very difficult for me to actually pull the trigger and make the decision to sell part of my collection, the part that i am selling. i just think it's time to let somebody else tr sure them a honor them the way i have for the last 30 years. >>> it's tuesday, december 17th, 2019. this is the "cbs morning news." >>> deadly storms. a tornado outbreak in the deep south causes destruction, and there's more dangerous ice and snow on the way for tens of millions. >>> for the record, house lawmakers announce how they'll vote tomorrow on the articles of impeachment. >>> and midair emergency. flames force an airliner to land unexpectedly. captioning funded by cbs captioning funded by c >>> good morning from the studio 57 newsroom at cbs news headquarters in new york. good to be with yo