Hello everyone!

I work at a publishing company and we currently have a very well known and very well stablished online publication. I can't reveal which it is or what we are going to do because some of the information is confidential at this time.

Let's imagine that the publication is about aviation, with a strong focus on civil aviation. Like for example: www.flyingmag.com (I'm not related in any way to that publication, I just googled it to use it as an example).

Now imagine that we want to create a sister publication that focuses also on aviation, but specific to military. Let's call it AirForceMag. This second publication would have strong ties to the original one and it will be clear it comes from the same people, it's just the focus of the publication that changes. Some articles published at AirForceMag would be linked from the main publication, and some articles published at the main publication would be linked from the military publication.

There would be no duplicate content either, the editorial team is the same, they just decide which story goes on which publication at the time of publishing and if the story will be featured and linked at the other publication as well.

We will of course register a domain name for the new publication, let's say AirForceMag.com. However at the time of hosting the publication we have 2 options:

Use the new domain and everything stays at www.AirForceMag.com Create a subdomain under the main publication airforcemag.flyingmag.com and have the new domain redirect there with a 301.

In terms of branding, readers, advertisers, it doesn't make much of a difference according to the reasearch we've made on the matter, so the decision comes down to SEO pretty much.

I've been to countless posts out there to learn about pros and cons for SEO and I still haven't come up with the decision.

How beneficial would be for the new website to be under the same, well stablished authoritative domain?

If we put it under the new domain only, would that be beneficial in any way for SEO, taking into account they'd be constantly linking each other's articles?

All opinions are welcome.