Question: Who is the father of the author of Royal Bengal Rahashya?

full_context: Document 1: The Inner Eye: The Inner Eye is a 1972 short documentary film made by Satyajit Ray on Benode Behari Mukherjee, a blind artist and a teacher from Visva-Bharati University, a university founded by Rabindranath Tagore at Santiniketan. The twenty minutes documentary features the life and works of Mukherjee in the form of paintings and photographs, starring himself. The documentary covers his journey from childhood till his blindness along with much of his works and features his words, "Blindness is a new feeling, a new experience, a new state of being". The documentary was awarded as Best Information Film (Documentary) at 20th National Film Awards in 1972.
Document 2: Badshahi Angti (film): Badshahi Angti ( "The Emperor's Ring") is a 2014 Bengali thriller film directed by Sandip Ray, based on the novel of the same name by Satyajit Ray, starring Abir Chatterjee and Sourav Das as Feluda and Topse respectively. The film was released on 19 December 2014. It is the first film which stars Abir Chatterjee as Feluda. This was going to be a reboot to previous Feluda film series after "Royal Bengal Rahashya." But in 2016 Sandip Ray cancelled the reboot series because Abir Chatterjee started a new version of film series based on Byomkesh Bakshi franchise under Shree Venkatesh Films and Surinder Films. The other reason was the new Feluda movie Sandip Ray intended to make under a Mumbai-based production house Eros International, but Abir has a strict contract with Shree Venkatesh Films and Surinder Films.
Document 3: Mahasankatey Shonku: Mahasankatey Shonku ("Shonku in Deep Peril") is a Professor Shonku series book written by Satyajit Ray and published by Ananda Publishers in 1977. Ray wrote the stories about Professor Shanku for Bengali magazines "Sandesh" and "Anandamela". This book is a collection of three Shonku stories.
Document 4: Satyajit Ray: Ray directed 36 films, including feature films, documentaries and shorts. He was also a fiction writer, publisher, illustrator, calligrapher, music composer, graphic designer and film critic. He authored several short stories and novels, meant primarily for young children and teenagers. Feluda, the sleuth, and Professor Shonku, the scientist in his science fiction stories, are popular fictional characters created by him. He was awarded an honorary degree by Oxford University.
Document 5: Subrata Mitra: Subrata Mitra (12 October 1930 – 7 December 2001) was an Indian cinematographer. Acclaimed for his work in "The Apu Trilogy" (1955–1959), Mitra is often considered one of the greatest of Indian cinematographers.
Document 6: Two (1964 film): Two: A Film Fable is a 1964, black-and-white short film directed by the Indian director Satyajit Ray. The film was made under the banner of Esso World Theater at the request of a non-profit American public broadcasting television, PBS. It was made as part of a trilogy of short films from India. The other two films in the trilogy featured Indian Sitar player, Pandit Ravi Shankar and a Ballet troupe from Mumbai, then known as "Bombay". Ray, who worked prominently for Bengali cinema, was requested to make a film in English language with a Bengali setting, however Ray being an admirer of silent film decided to make a film without any dialogue as a tribute to the genre.
Document 7: Sikkim (film): Sikkim is a 1971 Indian documentary about the nation of Sikkim, directed by Satyajit Ray. The documentary was commissioned by the Chogyal (King) of Sikkim at a time when he felt the sovereignty of Sikkim was under threat from both China and India. Ray's documentary is about the sovereignty of Sikkim. The film was banned by the government of India, when Sikkim merged with India in 1975. In 2000, the copyright of the film was transferred to the Art and Culture Trust of Sikkim. The ban was finally lifted by the Ministry of External Affairs (MEA) in September 2010. In November 2010 the director of the Kolkata film festival stated that upon screening the documentary for the first time, he received an injunction from the court of Sikkim again banning the film.
Document 8: Seemabaddha: Seemabaddha ( "Shimabôddho"; English title: "Company Limited") is a 1971 social drama Bengali film directed by Satyajit Ray. It is based on the novel "Seemabaddha" by Mani Shankar Mukherjee. It stars Barun Chanda, Harindranath Chattopadhyay, and Sharmila Tagore in lead roles. The film was the second entry in Ray's Calcutta trilogy, which included "Pratidwandi" ("The Adversary") (1970) and "Jana Aranya" ("The Middleman") (1976). The films deal with the rapid modernization of Calcutta, rising corporate culture and greed, and the futility of the rat race.
Document 9: Bibhutibhushan Bandyopadhyay: Bibhutibhushan Bandyopadhyay () (12 September 1894 – 1 November 1950) was an Indian Bengali author, and one of the leading writers of modern Bengali literature. His best known work is the autobiographical novel, "Pather Panchali" ("The Song of the Road"). He was posthumously awarded the Rabindra Puraskar in 1951, the most prestigious literary award in West Bengal, for his novel "Ichhamati".
Document 10: Jalsaghar: Jalsaghar ( "Jalsāghar", "The Music Room") is a 1958 Indian Bengali drama film written and directed by Satyajit Ray, based on a popular short story by Bengali writer Tarasankar Bandyopadhyay, and starring Chhabi Biswas. It was the fourth feature film directed by Ray. The shooting was done at Nimtita Raajbari, in Nimtita village, 10 kilometres from Murshidabad.
Document 11: Satyajit Ray: Although they were Bengali Kayasthas, the Rays were 'Vaishnavas' (worshippers of Vishnu) as against majority Bengali Kayasthas who were 'Shaktos' (worshippers of the Shakti) .Sukumar Ray died when Satyajit was barely three, and the family survived on Suprabha Ray's meager income. Ray studied at Ballygunge Government High School, Calcutta, and completed his BA in economics at Presidency College, Calcutta then affiliated with the University of Calcutta,(now Kolkata)though his interest was always in fine arts. In 1940, his mother insisted that he studied at the Visva-Bharati University at Santiniketan, founded by Rabindranath Tagore. Ray was reluctant due to his love of Calcutta, and the low opinion of the intellectual life at Santiniketan. His mother's persuasion and his respect for Tagore finally convinced him to try. In Santiniketan, Ray came to appreciate Oriental art. He later admitted that he learned much from the famous painters Nandalal Bose and Benode Behari Mukherjee. Later he produced a documentary film, The Inner Eye, about Mukherjee. His visits to Ajanta, Ellora and Elephanta stimulated his admiration for Indian art.
Document 12: Anandamath: Anandamath (Bengali: আনন্দমঠ Anondomôţh; first English publication title: The Abbey of Bliss) is a Bengali fiction, written by Bankim Chandra Chattopadhyay and published in 1882. Set in the background of the Sannyasi Rebellion in the late 18th century, it is considered one of the most important novels in the history of Bengali and Indian literature. Its importance is heightened by the fact that it became synonymous with the struggle for Indian independence from the British Empire. The novel was banned by the British. The ban was lifted later by the Government of India after independence.
Document 13: Sukumar Ray (film): Sukumar Ray is a 1987 Bengali short documentary film made by Satyajit Ray on his father, Sukumar Ray. It was released during the birth centenary year of Sukumar Ray, who was born on 30 October 1887. The thirty minutes documentary features the life and some of the works by Sukumar Ray in the form of paintings, photographs and readings. This is the last documentary made by Satyajit Ray as a tribute to his father, before he died in 1992. The documentary used Sukumar Ray's photographs and paintings than video recording as the film was considerably a new medium in India when Sukumar Ray died in 1923.
Document 14: Royal Bengal Rahashya (novel): Royal Bengal Rahashya is a novel in Feluda Series created by the eminent author and director Satyajit Ray. It is of 88 pages and is published by Ananda Publishers Pvt. Ltd. in 1975. It was preceded by "Kailashey Kelenkari" and followed by "Joi Baba Felunath".
Document 15: Our Films, Their Films: Our Films, Their Films is an anthology of film criticism by noted Bengali filmmaker, composer and writer Satyajit Ray. Collecting articles and personal journal excerpts, it was first published in India in 1976; an English translation was published in The United States and United Kingdom in 1992. Some of articles were previously published in the bulletin of the Calcutta Film Society which Ray co-founded in 1947.
ground_truth: Sukumar Ray
sub_queries: Royal Bengal Rahashya >> author Answer: Satyajit Ray
Satyajit Ray >> father Answer: Sukumar Ray