Galaxy Spectral Lines Interactive Reference
JWST NIRCam WFSS reference for galaxy observations at any redshift
F356W grism (3.0–4.0 μm) + F444W grism (3.8–5.0 μm) used simultaneously
📊 All wavelengths are vacuum (Å) — sources: SDSS DR7, NIST ASD, Morton (2003, ApJS, 149, 205), Osterbrock & Ferland (2006)
z = 4.0 |
Lookback Time: ~12.5 Gyr |
Universe Age: ~1.2 Gyr
📡 Observed Wavelength Positions & JWST Coverage
1.0 μm
2.0 μm
3.0 μm
4.0 μm
5.0 μm
6.0 μm
Observable Lines
🔴 Emission Lines
Hydrogen Series
Lyman Series (n→1) — UV resonance
| Line | Rest λ (Å) | Obs λ (μm) | Transition | JWST |
|---|---|---|---|---|
| Lyα | 1215.670 | 0.608 | n=2→1 | ✗ |
| Lyβ | 1025.722 | 0.513 | n=3→1 | ✗ |
| Lyγ | 972.537 | 0.486 | n=4→1 | ✗ |
| Lyδ | 949.743 | 0.475 | n=5→1 | ✗ |
Balmer Series (n→2)
| Line | Rest λ (Å) | Obs λ (μm) | Rel. Flux | JWST |
|---|---|---|---|---|
| Hα | 6564.614 | 3.282 | 1.00 | ✓ |
| Hβ | 4862.721 | 2.431 | 0.35 | ✗ |
| Hγ | 4341.684 | 2.171 | 0.17 | ✗ |
| Hδ | 4102.892 | 2.051 | 0.10 | ✗ |
| Hε | 3970.072 | 1.985 | 0.06 | ✗ |
| H6 (Hζ) | 3889.064 | 1.945 | 0.04 | ✗ |
| H7 (Hη) | 3835.391 | 1.918 | 0.03 | ✗ |
| H8 | 3797.904 | 1.899 | 0.02 | ✗ |
| H9 | 3771.701 | 1.886 | 0.02 | ✗ |
| H10 | 3750.153 | 1.875 | 0.01 | ✗ |
Paschen Series (n→3) - Infrared
| Line | Rest λ (Å) | Obs λ (μm) | Transition | JWST |
|---|---|---|---|---|
| Pa α | 18756.0 | 9.38 | n=4→3 | ✗ |
| Pa β | 12821.6 | 6.41 | n=5→3 | ✗ |
| Pa γ | 10941.1 | 5.47 | n=6→3 | ✗ |
| Pa δ | 10052.1 | 5.026 | n=7→3 | ✗ |
| Pa ε | 9547.6 | 4.774 | n=8→3 | ✓ |
| Pa ζ | 9231.6 | 4.616 | n=9→3 | ✓ |
| Pa 8 | 9017.4 | 4.509 | n=10→3 | ✓ |
Brackett Series (n→4) - Far-Infrared
| Line | Rest λ (Å) | Obs λ (μm) | Transition | JWST |
|---|---|---|---|---|
| Br α | 40522.8 | 20.26 | n=5→4 | ✗ |
| Br β | 26258.7 | 13.13 | n=6→4 | ✗ |
| Br γ | 21661.2 | 10.831 | n=7→4 | ✗ |
| Br δ | 19450.7 | 9.725 | n=8→4 | ✗ |
| Br ε | 18178.6 | 9.089 | n=9→4 | ✗ |
Neon Lines (AGN / Ionization)
| Line | Rest λ (Å) | Obs λ (μm) | Notes | JWST |
|---|---|---|---|---|
| [NeV]λ3347 | 3346.790 | 1.673 | AGN tracer | ✗ |
| [NeV]λ3427 | 3426.843 | 1.713 | AGN tracer | ✗ |
| [NeIII]λ3870 | 3869.856 | 1.935 | Ionization diag | ✗ |
| [NeIII]λ3969 | 3968.590 | 1.984 | Blends with Hε | ✗ |
Oxygen Forbidden Lines
| Line | Rest λ (Å) | Obs λ (μm) | Notes | JWST |
|---|---|---|---|---|
| [OII]λ3727 | 3727.092 | 1.864 | Doublet (density) | ✗ |
| [OII]λ3730 | 3729.875 | 1.865 | Doublet (density) | ✗ |
| [OIII]λ4363 | 4364.436 | 2.182 | Auroral — Te diag | ✗ |
| [OIII]λ4959 | 4960.295 | 2.480 | Doublet 1:3 | ✗ |
| [OIII]λ5007 | 5008.239 | 2.504 | Doublet 3:1 | ✗ |
| [OI]λ6300 | 6302.046 | 3.151 | Shock / AGN | ✓ |
| [OI]λ6364 | 6365.536 | 3.183 | 1/3 of [OI]6300 | ✓ |
| [OII]λ7322 | 7321.977 | 3.661 | Te diagnostic | ✓ |
| [OII]λ7333 | 7332.590 | 3.666 | Te diagnostic | ✓ |
Helium Lines
| Line | Rest λ (Å) | Obs λ (μm) | Notes | JWST |
|---|---|---|---|---|
| He II λ4687 | 4687.015 | 2.344 | AGN / WR stars | ✗ |
| He I λ5877 | 5877.249 | 2.939 | Recombination | ✗ |
| He I λ6678 | 6679.995 | 3.340 | Recombination | ✓ |
| He I λ7065 | 7067.138 | 3.534 | Triplet | ✓ |
| He I λ10830 (weak) | 10829.091 | 5.415 | 2³P₀→2³S₁ (weak) | ✗ |
| He I λ10830 (med) | 10830.250 | 5.415 | 2³P₁→2³S₁ (medium) | ✗ |
| He I λ10830 (strong) | 10830.340 | 5.415 | 2³P₂→2³S₁ (strongest) — winds/AGN | ✗ |
Nitrogen & Sulfur Lines
| Line | Rest λ (Å) | Obs λ (μm) | Notes | JWST |
|---|---|---|---|---|
| [NII]λ5755 | 5756.185 | 2.878 | Auroral — Te diag | ✗ |
| [NII]λ6549 | 6549.860 | 3.275 | Doublet weak | ✓ |
| [NII]λ6584 | 6585.270 | 3.293 | Doublet strong — BPT | ✓ |
| [SII]λ6718 | 6718.290 | 3.359 | Density diag | ✓ |
| [SII]λ6732 | 6732.680 | 3.366 | Density diag | ✓ |
| [SIII]λ9069 | 9071.100 | 4.536 | Strong NIR | ✓ |
| [SIII]λ9532 | 9533.200 | 4.767 | Strong NIR | ✓ |
Argon Lines
| Line | Rest λ (Å) | Obs λ (μm) | Notes | JWST |
|---|---|---|---|---|
| [ArIII]λ7136 | 7137.770 | 3.569 | Ionization diag | ✓ |
| [ArIII]λ7751 | 7753.239 | 3.877 | Ionization diag | ✓ |
Iron Lines (NIR)
| Line | Rest λ (Å) | Obs λ (μm) | Notes | JWST |
|---|---|---|---|---|
| [Fe II] 1.257 μm | 12570.0 | 6.285 | Shock / AGN | ✗ |
| [Fe II] 1.644 μm | 16436.0 | 8.218 | Shock / SFR | ✗ |
UV Lines (AGN / High-z tracers)
| Line | Rest λ (Å) | Obs λ (μm) | Notes | JWST |
|---|---|---|---|---|
| N V λ1239 | 1238.821 | 0.619 | AGN / HII | ✗ |
| N V λ1243 | 1242.804 | 0.621 | AGN / HII | ✗ |
| Si IV λ1394 | 1393.755 | 0.697 | ISM / wind | ✗ |
| Si IV λ1403 | 1402.770 | 0.701 | ISM / wind | ✗ |
| C IV λ1548 | 1548.205 | 0.774 | Doublet — AGN | ✗ |
| C IV λ1551 | 1550.779 | 0.775 | Doublet — AGN | ✗ |
| He II λ1640 | 1640.420 | 0.820 | AGN / WR indicator | ✗ |
| O III] λ1661 | 1660.809 | 0.830 | Semi-forbidden doublet | ✗ |
| O III] λ1666 | 1666.150 | 0.833 | Semi-forbidden doublet | ✗ |
| Al III λ1855 | 1854.718 | 0.927 | AGN BLR | ✗ |
| Al III λ1863 | 1862.790 | 0.931 | AGN BLR | ✗ |
| C III] λ1907 | 1906.683 | 0.953 | Semi-forbidden doublet | ✗ |
| C III] λ1909 | 1908.734 | 0.954 | Semi-forbidden doublet | ✗ |
| Mg II λ2796 | 2796.352 | 1.398 | Doublet — AGN | ✗ |
| Mg II λ2804 | 2803.531 | 1.402 | Doublet — AGN | ✗ |
🔵 Stellar & ISM Absorption Lines
UV ISM / CGM Absorption
Vacuum wavelengths from Morton (2003, ApJS, 149, 205)
| Line | Rest λ (Å) | Obs λ (μm) | Notes | JWST |
|---|---|---|---|---|
| Si II λ1260 | 1260.422 | 0.630 | Strong ISM | ✗ |
| O I λ1302 | 1302.169 | 0.651 | ISM + geocoronal | ✗ |
| Si II λ1304 | 1304.370 | 0.652 | ISM | ✗ |
| C II λ1334 | 1334.532 | 0.667 | Strong ISM | ✗ |
| Fe II λ1608 | 1608.451 | 0.804 | ISM iron | ✗ |
| Al II λ1671 | 1670.787 | 0.835 | Strong ISM | ✗ |
| Si II λ1527 | 1526.707 | 0.763 | ISM | ✗ |
| Fe II λ2344 | 2344.214 | 1.172 | ISM iron complex | ✗ |
| Fe II λ2374 | 2374.461 | 1.187 | ISM iron complex | ✗ |
| Fe II λ2383 | 2382.765 | 1.191 | ISM iron complex | ✗ |
| Fe II λ2587 | 2586.650 | 1.293 | ISM iron complex | ✗ |
| Fe II λ2600 | 2600.173 | 1.300 | Strongest ISM FeII | ✗ |
| Mg I λ2853 | 2852.963 | 1.426 | ISM / stellar | ✗ |
Strong Stellar Features
| Line | Rest λ (Å) | Obs λ (μm) | Diagnostic | JWST |
|---|---|---|---|---|
| Ca II K | 3934.777 | 1.967 | Age indicator | ✗ |
| Ca II H | 3969.588 | 1.985 | Age indicator | ✗ |
| G-band | 4305.610 | 2.153 | CH molecular band | ✗ |
| Hβ abs | 4862.721 | 2.431 | Stellar Balmer abs | ✗ |
| Mg I b | 5176.700 | 2.588 | Metallicity | ✗ |
| Na I D | 5895.600 | 2.948 | ISM / stellar | ✗ |
| Hα abs | 6564.614 | 3.282 | Stellar Balmer abs | ✓ |
| Ca II λ8498 | 8500.360 | 4.250 | NIR triplet | ✓ |
| Ca II λ8542 | 8544.440 | 4.272 | NIR triplet | ✓ |
| Ca II λ8664 | 8664.52 | 4.33 | NIR triplet | ✓ |
Observable with current selection
Outside current coverage
🛰️ JWST NIRCam Grism Specifications
F356W Grism: λ = 3.0–4.0 μm, R ~ 1600, optimal for z = 4–6 Hα, [OIII], [SII] observations
F444W Grism: λ = 3.8–5.0 μm, R ~ 1600, optimal for z = 5–7 Hα, higher-z [OIII] observations
Observing Strategy: Use both grisms for optimal line coverage across different redshift ranges
📋 Selected Line Details
Click on any line in the tables above to see detailed information and observability.
Created by: Ronaldo Laishram
© 2025 Ronaldo Laishram | www.ronaldolaishram.com
Galaxy Spectral Lines Interactive Reference for JWST NIRCam Observations