Listener doesn't receive msgs if launchs Talker with system command

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In the example in the tutorial of subscriber and listener everything works well, subscriber sends and listener receives messages. Using Linux, why if I launch the subscriber program from the listener with the command system in a new terminal, the listener doesn't receive any messages?

    #include "ros/ros.h"
    #include <std_msgs/Int32.h>   
    #include <signal.h> 
    #include <sstream>
    int main(int argc, char **argv)
    {    
      ros::init(argc, argv, "talker");
      ros::NodeHandle n;
      ros::Publisher chatter_pub = n.advertise<std_msgs::Int32>("chat", 1);
      ros::Rate loop_rate(1);
      int count = 0;
      while (ros::ok())
      {
        std_msgs::Int32 msg;
        msg.data = getpid();
        ROS_INFO("%i", msg.data);
        chatter_pub.publish(msg);
        ros::spinOnce();
        loop_rate.sleep();
        ++count;   
   }    
    return 0;
}

LISTENER:

#include "ros/ros.h"
#include <std_msgs/Int32.h>

void chatterCallback(const std_msgs::Int32::ConstPtr& msg)
{
  ROS_INFO("I heard: [%i]", msg->data);
}

int main(int argc, char **argv)
{
 int  status = system("gnome-terminal -x ./talker");
 printf("STATUS: %d", status);

  ros::init(argc, argv, "listener");
  ros::NodeHandle n;
  ros::Subscriber sub = n.subscribe("chat", 1000, chatterCallback);
  ros::Rate loop_rate(1);
  int count = 0;
  while (ros::ok())
  {
    ros::spinOnce();
    loop_rate.sleep();


     ++count;
      }
  return 0;
}

STATUS:2