What exactly happened to the Norse? did they die out or just casually turn into modern day Scandinavians?

I think it's a good sign that you're already formulating your question in terms of 'the Norse' as opposed to the big-V 'Vikings' which is a very problematic term. Most scholars don't like big-V Vikings because the term suggests that there was a single Viking ethnicity, and that all big-V Vikings were somehow alike. We know this to be false, so now we talk about two things instead: (1) little-v vikings, who were pirates and raiders (vikingr was a job title, not an ethnicity); and (2) the Norse, which was anyone who spoke a variant of the Old Norse languages. But just like people of different backgrounds speak English today, people of diverse backgrounds spoke Norse in the Viking Age.

So it sounds to me that you're less interested in when viking activity ended and more interested in when Norse-speaking culture(s) diverged and turned into something else. The articles for you seem to be:

Lesley Abrams, 'Diaspora and Identity in the Viking Age', Early Medieval Europe 20 (2012): 17–38. {top recommendation}
Dawn Hadley, 'Viking and Native: Re-thinking Identity in the Danelaw', Early Medieval Europe 11 (2002): 45–70. {a great case study that hammers out some of the problems thinking through Norse/Viking ethnicity}

Regarding the term Viking and more general discussion on how we conceptualize the Viking Age and Viking-Age cultures, I'd point you to:

Stefan Brink, 'Introduction' and 'Who Were the Vikings?' in The Viking World, eds. Stefan Brink and Neil Price (Abingdon: Routledge, 2008), 1–7. {also a highly recommended volume; lots of great short reads by top scholars}
Fredrik Svanberg, Decolonizing the Viking Age 1 (Stockholm: Almqvist and Wiksell International, 2003). {focus on the introduction and the first chapter, skim the rest}