Start thread within member function using std::thread & std::bind

I have few queries with respect to below code snapshot.

1) With respect to pthread_create(), assume Thread_1 creates Thread_2. To my understanding Thread_1 can exit without join, but still Thread_2 will keep running. Where as in below example without join() I am not able to run thread and I am seeing exceptions.

2) In few examples I am seeing thread creation without thread object as below. But when I do the same, code is terminated.

std::thread(&Task::executeThread, this);

I am compiling with below command.
g++ filename.cpp -std=c++11 -lpthread

But still it terminate with exception. Is this right way of creating thread or is there any different version of C++ (In my project already they are compiling but not sure about the version).

3) In few examples of my project code, I am seeing below way of creating thread. But I am not able to execute with below example.

std::thread( std::bind(&Task::executeThread, this) );

Below is my code snapshot.

#include <iostream>
#include <thread>

class Task
{
    public:
    void executeThread(void)
    {
        for(int i = 0; i < 5; i++)
        {
           std::cout << " :: " << i << std::endl;
        }
    }

    void startThread(void);
};

void Task::startThread(void)
{
    std::cout << "\nthis: " << this << std::endl;

#if 1
    std::thread th(&Task::executeThread, this);
    th.join(); // Without this join() or while(1) loop, thread will terminate
    //while(1);
#elif 0
    std::thread(&Task::executeThread, this);  // Thread creation without thread object
#else
    std::thread( std::bind(&Task::executeThread, this) );
    while(1);
#endif
}

int main()
{
    Task* taskPtr = new Task();
    std::cout << "\ntaskPtr: " << taskPtr << std::endl;

    taskPtr->startThread();

    delete taskPtr;
    return 0;
}

Thanks & Regards

Vishnu Beema