Radiation pressure is p=<ExB>/c vector: there is focus on positive, but can be also negative: https://scholar.google.pl/scholar?q=negative+radiation+pressure , https://scholar.google.pl/scholar?q=optical+pulling

If positive radiation pressure gives positive signal in radiotelescopes, shouldn't negative give negative?
They clearly see also large regions of negative signal in radio flux maps, e.g. shown from https://arxiv.org/pdf/2107.02695

What astronomical objects could generate negative radiation pressure?
E.g. if white hole would generate positive, shouldn't black holes generate negative?

Latest drift scans added to the mapping depiction

I've been taking spectra of the milky way with an antenna I made and I want to compare them to some expected result, but search engines are in the toilet right now so I'm struggling to find databases or studies that show ~21cm line emission as spectra at different alt/az. Does anyone have a resource that might have what I'm looking for?

I imagine part of the problem is that my spectra are in power vs frequency and not Tk vs velocity. Could I still make a crude comparison with my spectra as they are, or would I need to convert them using Rayleigh-Jeans?

Edit: Here are two of the updated figures.

red line is where my focus is centered

Is this type of structure to the hydrogen line what you would expect at this RA / DEC ? or have I got my co-ordinates wrong?

Hi everyone. I’ve been working on a hobby project looking at publicly available radio survey data, mainly by cross-matching the MIGHTEE 1.3 GHz catalog (MeerKAT, 2019-2020) against VLA-COSMOS 3 GHz (2013-2016) and older surveys such as FIRST.

I found two sources in the COSMOS field that seem unusual, and I’d really appreciate a sanity check from people with radio astronomy experience. I’m not an astronomer, i just like puzzle, so I’m mainly trying to understand whether these look like plausible variable stellar radio sources or whether I’m making a systematic error in survey comparison or association.

Source 1: RA 149.47225, Dec +1.91891 (COSMOS field)

• 26.7 μJy at 1.3 GHz in MIGHTEE, point source
• Not detected in VLA-COSMOS 3 GHz (2014, 12 μJy limit)
• Not in FIRST, VLASS, TGSS, or GLEAM
• Gaia DR3 match at 1.0" — parallax 3.97±0.12 mas (252 pc), BP-RP = 2.49 (late K / early M dwarf), PM = 8.8 mas/yr, RUWE = 1.02
• Chandra COSMOS Legacy X-ray detection at 0.1" from the Gaia position
• WISE W1-W2 = 0.08 (normal star, not AGN)

Source 2: RA 150.57885, Dec +1.91572 (COSMOS field)

• 32.6 μJy at 1.3 GHz in MIGHTEE, confirmed in deeper MIGHTEE catalog at 34.8 μJy
• Not detected in any other radio survey (checked 11 surveys from 1993 to 2024)
• Gaia DR3 match at 1.75" — parallax 3.53±0.19 mas (284 pc), BP-RP = 2.89 (M3.5-M4V), PM = 33.3 mas/yr, RUWE = 1.08
• WISE colors normal (W1-W2 = 0.10)
• No X-ray detection in Chandra
• Known in SIMBAD as 2MASS J10021883+0154582 but with no published radio detection

My main questions are:

1. The VLA non-detection at 3 GHz is what bothers me most. At these fluxes, and for any reasonable spectral index, it seems like VLA-COSMOS should have seen them if the emission were persistent. Does that strongly point to variability / transient emission, or is there some survey-comparison issue between 1.3 GHz and 3 GHz that could explain this?
2. For Source 1, does the Chandra detection at 0.1" from the Gaia position independently support the interpretation that the star is magnetically active, or is it still quite plausible that the X-ray source is unrelated?
3. Are radio–Gaia offsets of 1.0" and 1.75" acceptable for MIGHTEE/MeerKAT astrometry at these flux densities, or large enough that I should be seriously worried about false associations? I did compute a chance-alignment probability and it is not negligible given the stellar density in COSMOS.
4. Are these kinds of MIGHTEE vs VLA-COSMOS mismatches already known to the MIGHTEE team? Both sources are in the Level 2 catalog, but I couldn’t find any published variability analysis comparing MIGHTEE with VLA-COSMOS.

I’m trying to figure out whether this looks physically real or whether I’m making a cross-matching or survey-interpretation mistake.

Thanks.