Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Conflict Airborne Conflict
Flight Crew Took Evasive Action
Human Factors; Environment - Non Weather Related
On our initial climbout of Las Vegas airport we were cleared to takeoff from Runway 26R. I don't remember if ATC told us about a traffic on the far end of the runway or not; anyhow we were cleared for takeoff. After rotation we raised the landing gear and before we could raise the flaps we had a TA for traffic that was initially 800 feet below us but the distance was closing in; my First Officer (FO) promptly turned on the remaining lights and started to look for the traffic. Considering the pitched up attitude and the night environment of Las Vegas strip it was hard to visually acquire the traffic.  Few seconds later the Traffic Alert (TA) became an RA and I was commanded to climb. I think I was at about 150 KIAS; I made sure to have enough speed to climb without stalling the plane; I did; so I pitched up the plane and followed the command bar. My FO quickly called the Tower to let them know about the event and everything was quickly concluded with no disruption for the flight. The event was concluded in a matter of a few seconds and I think we came within 500 feet vertically from the other traffic. I think it was an helicopter but I'm not sure. I don't know if the other traffic did not respect the Tower instruction or if the separation was not enough; but I don't think I did anything wrong to cause this event.
EMB-175 Captain reported an airborne conflict with another aircraft departing LAS.