The Lutheran church records for Sweden are available online for free via the Swedish Archives. It's best to use the Chrome browser to view images, as the images don't load in some other browsers. I scanned the following records -quickly- and found 1 Åström and 1 Oström or Öström, both in Svartbyn.
Here's the Household Exam for Boden, Överluleå parish, Norrbotten county. It covers the years 1831-40, the earliest Household Exam available. Boden starts on page 364 and ends on 406 or 407b (sid = page):https://sok.riksarkivet.se/bildvisning/C0035177_00094#?c=&am...
Here's the section for Svartbyn, Överluleå parish, Norrbotten county. Starts on page 408 and ends on 442. Oström was found on page 409 and Åström on page 418:https://sok.riksarkivet.se/bildvisning/C0035177_00142#?c=&am...
Oakland FamilySearch Library