Esther Norma Arrostito (January 17, 1940 – January 15, 1978) was an Argentine political activist and leftist militant, initially close to communist ideology, In 1970, she became one of the founders of the peronist revolutionary movement of which organization, along with Fernando Abal Medina, what was an Argentine leftist terrorist and urban guerrilla group, active during the 1960s and 1970s?