Schartmann-Sallmann family #germany

Catherine Claisse <catherine.claisse@...>

Hello I found I have ancestors in Germany, in Rott, Roetgen, North Rhine Westphalia. My ancestor's name was:

Johannes Jacob SCHARTMANN also found as Jois or Joes SCHARTMANN. He died in Rott,Roetgen,North Rhine Westphalia,GERMANY on the 4th of July Rott,Roetgen,North Rhine Westphalia,GERMANY. He got married with Maria Magdalena SCHWEITZER on the 29th of april 1795, same locatio, who died on the 7th of june 1827, same place. They got a son who was christened, Willem Jan, on the 26th of may 1796. Willem is found as SALLMANN/SALLMAN as well. He moved to NETHERLANDS first, where he got married to Sophia Steins, and then to Belgium to work. His descendance in Belgium is found as SCHARTMANN and SALLMANN.
I'm looking for ideas on how to find whether my ancestor's German family was Jewish and how to get more information on them.
Is there anyone who could help me? Thanks

Catherine Claisse, Florence italy