Actors David Duchovny of “The X-Files” and Tea Leoni of “Deep Impact” have welcomed their first child, a girl, into the world. The baby was born Saturday at an undisclosed Southern California hospital, said the couple’s publicist, Annett Wolf. The girl weighed 7 1/2 pounds and was 20 1/2 inches long at birth, said Wolf. The baby’s name was not immediately announced. Duchovny, 38, wed Leoni, 33, on May 6, 1997. It is his first marriage and her second. The child is a first for both.