Question: When did the operator of the RMS Celtic go out of business?

full_context: Document 1: SS Baltic (1871): SS "Baltic" was an ocean liner owned and operated by the White Star Line. "Baltic" was one of the first four ships ordered by White Star from shipbuilders Harland and Wolff after Thomas Ismay bought the company, and the third of the ships to be delivered.
Document 2: Oceanic (unfinished ship): The RMMV "Oceanic" (Royal Mail Motor Vessel) was the planned name of an unfinished ocean liner that was partially built by Harland and Wolff for the White Star Line. The ship was to have been the first -long ocean liner. It was intended to be the largest ocean liner for the White Star Line, thus it would have been larger than the earlier White Star giants, "Olympic", "Titanic", "Britannic", and "Majestic."
Document 3: White Star Line: White Star Line Former type Partnership Industry Shipping, transportation Fate merged with Cunard Line Successor Cunard White Star Line Founded 1845 (1845) in Liverpool, England Defunct 1934 Area served Transatlantic Parent Ismay, Imrie and Co. Website www.cunard.co.uk
Document 4: SS Cymric: SS "Cymric" was a steamship of the White Star Line built by Harland and Wolff in Belfast and launched on 12 October 1897. She had originally been designed as a combination passenger liner and livestock carrier, with accommodations for only First Class passengers. During the stages of her design layout, it became clearer to the designers at Harland and Wolff that combining passengers and livestock had become rather unpopular, so the spaces designated for cattle were reconfigured into Third Class accommodations. She departed Liverpool on her maiden voyage on 29 April 1898, arriving in New York City on 9 May 1898. She spent the first five years of her career on the White Star Line's main passenger service route between Liverpool and New York, until 1903 when she was transferred to the less traveled Liverpool-Boston route, which she sailed on for nine years before being returned to the New York route in 1912.
Document 5: RMS Gaelic (1885): RMS "Gaelic" was a passenger and cargo liner built for the White Star Line. She transported the first 102 Korean immigrants to the United States. Sold in 1905 for further service in the Pacific, she was scrapped in 1907.
Document 6: RMS Cedric: "Cedric" was laid down in 1902 at the shipyard of Harland and Wolff, Belfast. She was the second of White Star's series known as the "Big Four", the other three being , and . "Celtic" was the first ship to exceed Brunel's in overall tonnage, which was quite an accomplishment, considering Brunel's giant ship held the size record for almost 40 years. Except for the "Adriatic" all of these in turn, when built, would be the largest ship in the world for a short time. RMS "Cedric" was a 21,035-gross ton ship, long and abeam, with two funnels, four masts, two propellers and a service speed of . There was accommodation for 365 first-, 160 second- and 2352 third-class passengers, and a crew of about 350. She was launched in Belfast on 21 August 1902, in a private ceremony which included several guests, amongst others William Pirrie, the chairman of Harland and Wolff and Bruce Ismay, chairman of White Star Line. RMS "Cedric" commenced her maiden voyage from Liverpool to New York on 11 February 1903. This was the only route on which she was ever used, although "Cedric" was also sometimes used for winter cruises to the Mediterranean.
Document 7: American Export-Isbrandtsen Lines: American Export-Isbrandtsen Lines, New York, was the leading US-flag shipping company between the U.S. east coast and the Mediterranean from 1919 to 1977, offering both cargo ship services and passenger ship services, until it declared bankruptcy and was acquired by Farrell Lines, New York.
Document 8: RMS Celtic (1901): RMS "Celtic" was an ocean liner owned by the White Star Line. The first ship larger than the in gross tonnage (it was also longer), Celtic was the first of a quartet of ships over 20,000 tons, dubbed The Big Four.
Document 9: RMS Oceanic (1870): RMS "Oceanic" was the White Star Line's first liner and an important turning point in passenger liner design. Entering service in 1871 for Atlantic crossings, she was later chartered to Occidental and Oriental Steamship Company (O&O) in 1875. The ship provided passenger service for O&O in the Pacific until 1895 when she was sold for scrap.
Document 10: RMS Teutonic: The RMS "Teutonic" was a steamship built for the White Star Line in Belfast and was the first armed merchant cruiser.
Document 11: Williams & Guion Black Star Line: The Black Star Line was the name used by American sailing packets owned by the New York firm of Williams and Guion from 1848 to 1866. The line owned 18 ships on the Liverpool-Queenstown-New York route. The line was shut down in 1863 because of the success of newer, faster liners and the danger of transatlantic travel during the American Civil War.
Document 12: RMS Aquitania: RMS "Aquitania" was a British ocean liner of Cunard Line in service from 1914 to 1950. She was designed by Leonard Peskett and built by John Brown & Company in Clydebank, Scotland. She was launched on 21 April 1913 and sailed on her maiden voyage from Liverpool to New York on 30 May 1914. "Aquitania" was the third in Cunard Line's "grand trio" of express liners, preceded by and , and was the last surviving four-funnelled ocean liner. Shortly after "Aquitania" entered service, World War I broke out, during which she was first transformed into an auxiliary cruiser before being transformed into a troop transport and a hospital ship, notably as part of the Dardanelles Campaign.
Document 13: RMS Adriatic (1906): RMS "Adriatic" was an ocean liner of the White Star Line. She was the fourth of a quartet of ships measuring over 20,000 tons, dubbed The Big Four. The ship was the only one of the four which was never the world's largest ship; however, she was the fastest of the Big Four. "Adriatic" was the first ocean liner to have an indoor swimming pool and a Turkish bath.
Document 14: Saint Helena: From 1958, the Union Castle shipping line gradually reduced its service calls to the island. Curnow Shipping, based in Avonmouth, replaced the Union-Castle Line mailship service in 1977, using the RMS (Royal Mail Ship) St Helena.
Document 15: SS Britannic (1874): "Britannic" was a single-screw passenger steamship equipped with sails built for the White Star Line's North Atlantic run. It was initially to be called "Hellenic", but, just prior to her launch, her name was changed to "Britannic". Together with her sister "Germanic", "Britannic" sailed for nearly thirty years, primarily carrying immigrant passengers on the highly trafficked Liverpool to New York City route. In 1876 it received the Blue Riband, both westbound and eastbound, by averaging almost .
ground_truth: 1934
sub_queries: RMS Celtic >> operator Answer: White Star Line
when did White Star Line go out of business Answer: 1934