Question: What is a large mountain massif in Antarctica that is 21 km long and 13 km wide and lies within the Sentinel Range of the Ellsworth Mountains, named after  a United States Representative from Georgia ?
Context: Petvar Heights (Bulgarian: "Петварски възвишения" , ‘Petvarski Vazvisheniya’ \'pet-var-ski v&-zvi-'she-ni-ya\) are the heights rising to 2400 m at Mount Mullen in southeast Sentinel Range, Ellsworth Mountains in Antarctica.  The heights occupy an oval shaped area with a diameter of 21 km, separated from the rest of Sentinel Range by Wessbecher Glacier to the southwest, Kasilag Pass to the west, and Kornicker Glacier to the northwest and north.  Their interior is drained by Hudman, Carey, Razboyna, Gabare and Divdyadovo Glaciers. Sabazios Glacier (Bulgarian: "ледник Сабазий" , ‘Lednik Sabazios’ \'led-nik sa-'ba-ziy\) is the 19 km long and 6 km wide glacier on the east side of northern Sentinel Range in Ellsworth Mountains, Antarctica.  It is situated south of Newcomer Glacier, west of Anchialus Glacier, north of Embree Glacier, and east of Zhenda Glacier and Skaklya Glacier.  The glacier drains the east slopes of Mount Alf and Mount Sharp, and the north slopes of the side ridge that trends 9.15 km from Mount Dalrymple on the main crest of Sentinel Range east-northeast to Robinson Pass, flows northwards and joins Newcomer Glacier northwest of Mount Lanning in Sostra Heights. Divdyadovo Glacier (Bulgarian: "ледник Дивдядово" , ‘Lednik Divdyadovo’ \'led-nik div-'dya-do-vo\) is the 8 km long and 3 km wide glacier in Petvar Heights on the southeast side of Sentinel Range in Ellsworth Mountains, Antarctica situated northeast of Carey Glacier and southeast of Drama Glacier.  It is flowing northeastwards, then north of Ruset Peak turning east-southeastwards to leave the range southeast of Long Peak. Jacobsen Valley (Bulgarian: "долина Якобсен" , ‘Dolina Jacobsen’ \do-li-'na 'ya-kob-sen\) is the shallow valley in Vinson Massif, Sentinel Range in Ellsworth Mountains, descending northwards from the summit of Antarctica Mount Vinson (4892 m).  It is 3.5 km long and 1.2 km wide, and is bounded to the west by Branscomb Peak and Galicia Peak, and to the east by a minor ridge running between the east side of Mount Vinson to the south and Goodge Col to the north.  Draining the valley is a glacier tributary to Branscomb Glacier, part of the classical route to the summit Mount Vinson. Vinson Plateau (Bulgarian: "плато Винсън" ] ) is the summit plateau of Vinson Massif, Sentinel Range in Ellsworth Mountains, Antarctica.  It extends for 9 km between Goodge Col and Hammer Col linking it to the north-central part of Sentinel Range to the north-northwest and to Craddock Massif to the south-southeast respectively, and 4.5 km wide between Branscomb Peak and Silverstein Peak to the west and Schoening Peak and Marts Peak to the east.  Elevation from 4000 m to 4600 m above sea level.  Rising from the plateau is the summit of Antarctica Mount Vinson (4892 m), and several other peaks higher than 4700 m, albeit of modest prominence: Clinch Peak (4841 m), Corbet Peak (4822 m), Silverstein Peak (4790 m), Schoening Peak (4743 m) and Hollister Peak (4729 m).  The lower peaks of Fukushima (4634 m) and Opalchenie (4500 m) stand at the south extremity of the plateau.  Its central part is drained by Roché Glacier and a tributary glacier in Jacobsen Valley, with both of them joining Branscomb Glacier. Gildea Glacier is a glacier 10 km long and 5 km wide flowing southwestward from Craddock Massif between Mount Slaughter and Mount Atkinson into Nimitz Glacier, in the Sentinel Range of the Ellsworth Mountains, Antarctica.  The upper portion of the glacier also receives ice from Hammer Col and southern Vinson Massif. Vinson Massif ( ) is a large mountain massif in Antarctica that is 21 km long and 13 km wide and lies within the Sentinel Range of the Ellsworth Mountains.  It overlooks the Ronne Ice Shelf near the base of the Antarctic Peninsula.  The massif is located about 1200 km from the South Pole.  Vinson Massif was discovered in January 1958 by U.S. Navy aircraft.  In 1961, the Vinson Massif was named by the Advisory Committee on Antarctic Names (US-ACAN), for Carl G. Vinson, United States congressman from the state of Georgia, for his support for Antarctic exploration.  On Nov. 1, 2006, US-ACAN declared Mount Vinson and Vinson Massif to be separate entities. Kopsis Glacier (Bulgarian: "ледник Копсис" , ‘Lednik Kopsis’ \'led-nik 'kop-sis\) is a 13 km long and 4 km wide glacier on the east side of north-central Sentinel Range in Ellsworth Mountains, Antarctica that is draining northeastwards from Panicheri Gap, Voysil Peak and Mount Gozur to join Embree Glacier northwest of Mirovyane Peak. The Ellsworth Mountains are the highest mountain ranges in Antarctica, forming a 360 km long and 48 km wide chain of mountains in a north to south configuration on the western margin of the Ronne Ice Shelf in Marie Byrd Land.  They are bisected by Minnesota Glacier to form the Sentinel Range to the north and the Heritage Range to the south.  The former is by far the higher and more spectacular with Mount Vinson (4,892 m) constituting the highest point on the continent. Carl Vinson (November 18, 1883 – June 1, 1981) was a United States Representative from Georgia.  He was a Democrat and served for more than 50 years in the United States House of Representatives.  He was known as "The Father of the Two-Ocean Navy".  He is the longest-serving member of the United States House of Representatives from the state of Georgia.
Answer: Vinson Massif